ﺔﻴﺴﺩﻨﻬﻟﺍ ﺎﻴﺠﻭﻟﻭﻴﺠﻟﺍ ﺭﺭﻘﻤ GEOLOGY EEG... · eeg 341 ﺔﻴﺳﺪﻨﻬﻟا ﺎﻴﺟﻮﻟﻮﻴﺠﻟا رﺮﻘﻣ ﻲﺛرﺎﺤﻟا

EEG 341عباس بن عيفان الحارثي مقرر الجيولوجيا الهندسية / أد جامعة الملك عبدالعزيز آلية علوم األرض قسم الجيولوجيا الهندسية و البيئية

٠

جامعة الملك عبدالعزيز كلية علوم األرض

قسم الجيولوجيا الهندسية و البيئية

مقرر الجيولوجيا الهندسيةمقرر الجيولوجيا الهندسية ))٣٤١٣٤١ض جه ض جه ((

EEnnggiinneeeerriinngg GGeeoollooggyy

((EEEEGG 334411))

اعداداعداد

عباس بن عيفان الحارثيعباس بن عيفان الحارثي./ ./ أ دأ د


١

Faculty of Earth Sciences King Abdul-Aziz University

Course Description (Theoretical)

Department: Engineering and Environmental Geology Course Symbol: EEG Number: 341

Course name: Engineering Geology

Pre-requisite Courses: EEG 311, EEG 322 Course description: - Engineering geological consideration, description of soils and rock masses. Classification of rock masses for engineering purposes. Engineering geological maps and their applications. Requirement of conducting Engineering Geological studies and Writing Reports, Rock and soil improvement such as grouting, drains and reinforcement of ground (2 days Field Trips) Course objectives:

1. To outline the contribution of engineering geology to the civil and mining works 2. To explain the classical approach to solve an engineering geological problem 3. The extensive uses of engineering geology maps 4. The role and effect of engineering geology in the improvement of earth materials

General references for course: (Books/Journals…etc.) 1. Engineering Geology and Geotechnics by BELL, F. G., 1980. 2. Engineering Geology: Rock Engineering in Construction by GOODMAN, R.E.,

1993 3. Engineering Geology: An Environmental Approach by RAHN, P. H., 1986 4. Engineering Geology by ZARUBA, Q., and MENCL, V., 1976

Internet links: Geology and Geological Engineering Geotechnical and Geoenvironmental Software Directory Geophex, Ltd. GeoLine SpringerLink: Bulletin of Engineering Geology and the Engineering Geology Journals in engineering geology, earth science, environment, ...

Engineering Geology Course outcome: The student will be trained to know the description of soil and rock masses for engineering purposes and is also expected to know the following:

1. Engineering geological maps and its applications. 2. Rock engineering properties and the geotechnical problems they cause. 3. The various techniques for soil and rock improvement.

Scheme of assessment: 3 exams: 30% Field Trip: 10% Attendance: 10% Lab work: 25% Final exam: 25%


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Time Table for Course Lectures Week Test Name References

1 Introduction: Definition, purpose and scope See above 2 The broad scope of engineering geology 3 Functions of engineering geology

First Exam

4 Types of Maps 5 Engineering geological map. Geohazards maps 6 Comparison between geological and engineering

maps,. 7 Description and classification systems of soil

Second Exam

8 Description and classification systems of Rocks 9 BGD system 10 Geological Society system 11 IAEG system, RMR system 12 Third Exam13 Requirement of conducting Engineering

Geological studies, Engineering Geological Reports

14 Rock and soil improvement such as grouting, drains and reinforcement of ground

15 Rock and soil improvement such as grouting, drains and reinforcement of ground

16 Final Exam


٣

Time Table for Course Lab Work

Week Test Name References 1 Review: Engineering properties of soils and rock. 2 Flowchart function 3 Types of Maps Exam 1 4 Classification of engineering geological maps 5 Single purpose map 6 Multipurpose & Comprehensive Maps 7 Soil Classification( USCS) Exam 2 8 Description and classification systems of Rocks (Review) 9 Zonation BGD – system 10 Rock Mass Description System by GS 11 Rock and Soil Descrip. & Class. For Eng. Geol. Mapping

(IAEG) 12 RMR System Exam 3 13 Conducting Engineering geological study 14 Example of Writing Eng. Geol. reports 15 Lab Final Exam


٤

قسم الجيولوجيا الهندسية و البيئية ٣٤١قم المقرر ر ض جه -:رمز المقرر

٣٢٢و ض جه ٣١١المتطلبات السابقة ض جه -:وصف المقرر

، الخرائط و مجاالت أعمالها، االعتبارات الجيولوجية الهندسية ااتهمامتعريف الجيولوجيا الهندسية ، اهتأنظمة و صف و تصـنيف الكتـل الجيولوجية الهندسية و أنواعها، أنظمة و صف و تصنيف التربة ،

المشاكل الهندسية في التربة و الصخور . الصخرية ورسم الخرائط الجيولوجية الهندسية و كتابة التقارير . وطرق معالجتها

المراجع العلمية للمقرر1. Engineering Geology and Geotechnics by BELL, F. G., 1980. 2. Engineering Geology: Rock Engineering in Construction by GOODMAN, R.E.,

1993 3. Engineering Geology: An Environmental Approach by RAHN, P. H., 1986 4. Engineering Geology by ZARUBA, Q., and MENCL, V., 1976

Internet links: Geology and Geological Engineering Geotechnical and Geoenvironmental Software Directory Geophex, Ltd. GeoLine SpringerLink: Bulletin of Engineering Geology and the Engineering Geology Journals in engineering geology, earth science, environment, ...

Engineering Geology -:المطلوب من المقرر

فهم الطالب للجيولوجيا الهندسية و اهدافها و مجاالت عملها -١ معرفته بانواع الخرائط الهندسية وانظمة رسمها و تصنيفها -٢ .تطبيق انظمة و صف و تصنيف التربة و الصخور لألغراض الهندسية و لرسم الخرائط الجيولوجية الهندسية -٣ .راسات و آتابة التقارير في مجال الجيولوجيا الهندسيةمعرفة طرق اجراء الد -٤ .التعرف على المشاآل الهندسية للتربة و الصخور وطرق معالجتها -٥

. :طرق التقييم و توزيع الدرجات

3 exams: 30% Field Trip: 10% Attendance: 10% Lab work: 25% Final exam: 25%


٥

اجليولوجيا اهلندسية

Engineering Geology

:عنوان المنهج ينقسم إلى قسمين الجيولوجيا و الهندسة و آل مصطلح له توضيحه .مصطلح يعني علم األرض : الجيولوجيا - .وهو يعني مجال الهندسة : الهندسية -

- : تعريف الجيولوجيا الهندسية •المتكونات الجيولوجية لألرض و ما تحتويه من أنواع صخور و تشققات و نالرابط بيالعلم هو

معرفة تقنيـة ومياه و تراكيب و تضاريس و بين األعمال الهندسية سواءا المدنية أو التعدينية .أستخدم األرض أو مواد األرض لإلنشاء و للبناء

والبيئيـة بجميع التطبيقات الهندسـية رضيةاأليختص بعالقة خواص القشرة تطبيقيهو علم والخزانـات الطـرق السدود على سبيل المثال األرضيةبداخل القشرة أوفوق إنشائهايتم التي

.البترول أبارالمناجم األنفاقالجسور

نشأة األرض، أنواع الصخور، األشكال -:معرفة التاليالجيولوجيا الهندسية و يتطلب تخصصالتربـة، و للصخور ) الهندسية(الميكانيكية و ) الطبيعية (الفيزيائية الخواص خور،البنائية للص

نفاق، السدود والخزانات وعالقتها بخواص ألا جيولوجيةو تحليل و دراسة المياه تحت األرضية، .الخرائط الجيولوجية ،الجيولوجيالطرق السيزمية للمسح و معرفة نتائج التربة،

المنجمية والبيئية، و يعني قات الجيولوجيا في األعمال الهندسية المدنية وبتطبي التخصصويهتم المخاطر الهندسية بتخريج جيولوجيين في الجيولوجيا الهندسية أو البيئية للقيام بإستنتاجات وتقييم

.والطبيعية التي قد تنتج أو تصاحب العمليات اإلنشائية والبيئية

لديه إلمام بالعلم الجيولوجي من طبقات األرض و الحركات و البد للجيولوجي الهندسي يكون

البنائية و تضاريس األرض و التراكيب المعدنية و المنجمية و نوعية الصخر و لديـه إلمـام كذلك بجيولوجيا المياه السطحية و الجوفية و بيئة ترسيب الصخور الرسوبية و طريقة تكون و

بالتصنيف الحقلي للصخور و أنواعها و الشقوق و م تحول الصخور المتحولة و يكون لديه إلماالفواصل و انواعها و قيمة ميولها و لديه قدرة على رسم و قـراءة الخـرائط الجيولوجيـة و

.تحديد المواقع و عمل الحدود بين الصخور المختلفة

كما يجب على الجيولوجي الهندسي كما يكون لديه إلمام و دراسة علـم المسـاحة و -س و الجيوفيزياء ليكون قادر على دراسة تطبيقاتها و آثارها على المنشآت و التضاري

من الضروريات أن يكون المتخصص أن يكون لديه علم بدراسة علم ميكانيكا التربـة و ميكانيكا الصخور و مواد البناء و لديه القدرة على إجراء التجارب المعملية للتربـة

.و الصخور و الركام


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ذه المادة أن تتعرف و تدرس الخواص الهندسية للتربة و الصـخور و و من أهمية ه -طرق تصنيفها و طرق وصفها للتمكن مـن دراسـة و فحـص المواقـع األرضـية

.لألغراض الهندسية

و يكمل هذه الدراسة كتابة تقرير و رسم خرائط جيولوجية هندسية للموقع المراد إقامة -ولوجية و التركيبية إضـافة إلـى الخـواص المنشأة عليه محتويا على الخواص الجي

.الهندسية المعتمدة لمثل هذه الدراسة

:أهم أعمال المهندس الجيولوجي

فحص المواقع واالختبارات الميدانيـة وتقيـيم التضـاريس األرضـية لألغـراض .١

. الجيولوجية الهندسية

المـدن األنفاق والكباري والسدود والمنحدرات الصـخرية و دراسة مواقع الطرق و .٢

. وحماية الشواطئ من الناحية الجيولوجية الهندسية

تقييم اآلثار الناتجة عن مخاطر السيول والفيضانات والزالزل والبـراكين والتصـحر .٣

. وإيجاد الحلول المناسبة لها

أهداف الجيولوجيا الهندسية

.المساهمة في حل المشاكل الهندسية والبيئية للمصادر الطبيعية - ١

المواقع واالختبارات الميدانية وتقييم التضاريس األرضية لألغراض الجيولوجية فحص - ٢

.الهندسية

المدن األنفاق والكباري والسدود والمنحدرات الصخرية و الطرق و دراسة مواقع - ٣

.وحماية الشواطئ من الناحية الجيولوجية الهندسية

والزالزل والبراكين والتصحر وإيجاد تقييم اآلثار الناتجة عن مخاطر السيول والفيضانات - ٤

.الحلول المناسبة لها

وتقديم البحوث . البيئية الطبيعية من كل ما يهددها ويلوثها المساهمة في التوعية - ٥

.والدراسات العلمية في مجاالت الجيولوجيا الهندسية والبيئية


٧

-: (Function of Engineering Geologist) دور و مهام الجيولوجي الهندسي •

:عمل الجيولوجي الهندسي يلخص في االتي . Interpretation of the ground conditions فحص المواقع األرضية - ١ . Exploration and assessment االآتشاف و التقييم - ٢ . Identification of hazards تعيين األخطار - ٣

العمل الجيولوجي الهندسي

فحص المواقع األرضية

الهندسة علم األرض

نوع التربة نوع الصخر سمك التربة سمك الصخر مستوى الماء

االآتشاف والتقييم

التعدين مصادر المياه الجوفية

التوفر عيةالنو

الكمية

النفط مواد البناء

الرآام

النوعية الكمية

األسمنت الرمل

تحديد المخاطر

التنقيب استقرار المنحدرات استقرار األنفاق

السبخة الهبوط التآآل

البناء الهبوط االنهيار

الكثبان الرملية حرآتها

المنخفضة ة الق

الجبلية الطرقاستقرار المنحدرات نظم التصريف

األبنية اإلهتزازات األساسات

األساسات الضحلة - ١ األساسات العميقة - ٢


٨


٩

Definition and Scope of Engineering Geology

Engineering geology forms the bridge between geology and engineering. It is mainly concerned with the application of geology to civil and mining engineering practice. The purpose is to ensure that geological factors affecting the planning, design construction and maintenance of engineering works and the development of groundwater resources are recognized, adequately interpreted and presented for use in engineering practice.

: تعريف

واألعمال الهندسية واألخذ في االعتبار ) الصخور والتربة ( الجيولوجيا الهندسية هي الرابط بين المواد الجيولوجية العوامل الجيولوجية المؤثرة على

الصيانة -٤البناء -٣التصميم -٢التخطيط -١

In engineering geology basic knowledge is required of the following:

- General Geology - Surveying - Geomorphology

- Remote Sensing - Hydrology

-Seismic, Geophysics - Soil Mechanics

- Rock Mechanics - Concrete, Aggregate

- Foundation - Road pavement of construction

A Much greater knowledge is required of site in investigation practice such as :

Boring Engineering geophysics Sampling Photo geology Lab in situ testing Engineering geological mapping

This knowledge is printed on background of with emphasis on structural geology , geomorphology , Sediment logy And there must be information on the use of computers in data analysis and geological mapping . Functions of Engineering Geologist The engineering geologist can contribute on the followings;

Interpretation of the ground conditions Exploration and assessment Identification of hazards


١٠

تطبيقات الجيولوجيا الهندسية

قد بدأ منذ أن بدأ اإلنسان بتشييد أبنيته على سطح و التعدينية إن الترابط بين علم الجيولوجيا والهندسة المدنية .على الرغم من التباين الواضح بينهما , األرض

وكذا فـإن معرفـة , لهندسية إن تطبيق المبادئ الجيولوجية في االكتشافات الهندسية تعود بالنفع على العلوم الذا تعتبر , المكونات الجيولوجية للتربة والصخور سيساعد في معرفة مدى توازن المنشآت الهندسية وإدامتها

وذلـك , الجيولوجيا الهندسية أحد الجوانب التطبيقية لعلم الجيولوجيا وتشكل حلقة الوصل مع الهندسة المدنية إن المهندس المدني غير مؤهل للقيام , قليل من المشاكل الهندسية ذات العالقة بتطبيق مبادئ علم الجيولوجيا للت

بدراسة جيولوجية متكاملة وفي الوقت نفسه فإن الجيولوجي ال يتمكن من تطبيق المبادئ الجيولوجية في حـل مهنـدس لذا فإن المسافة بين المهندس المدني والجيولـوجي يملـؤه اآلن مـا يسـمى بال , المشاكل الهندسية

. الجيولوجي فالمهندس الجيولوجي على معرفته الكاملة بالمبادئ الجيولوجية يستطيع أن يعمل في عدة مجـاالت هندسـية

.فضالً عن المجاالت التي يستلزم إجراء تحريات جيولوجية أولية ومفصلةمل في عمليات استخراجها بإمكان المهندس الجيولوجي أن يع ففي مجال الكشف عن الثروات الطبيعية و •

فيستخدم طرق الكشف السطحية والجويـة وكـذا , الكشف عن النفط والخامات المعدنية والمياه الجوفية وكذا استخدام طرق الكشف التحت سـطحية والتـي , الموقعية التنقيب وإجراء الفحوصات المختبرية و

. تعتمد على األجهزة الجيوفيزيائية المتنوعة

بإمكان المهندس الجيولوجي العمل في مجال إنشاء السدود والخزانـات المائيـة وفي المجاالت الهندسية •وإيجاد الحلول والمعالجات المناسبة لتفادي المشاكل المتوقعة عند , بإختيار المواقع االفتراضية المناسبة

ـ اإلنشاء وتحديد مناطق الضعف والفجوات الداخلية ومشـاكل التح االهتـزازات اإلنزالقـات و ية وشاألساسية والمستحثة من جراء تجمع الحجم الهائل للمياه في الخزانات ومراقبة جسم السد بعد اإلنشاء من

.خالل مجموعة من األجهزة الجيوفيزيائية الخاصة

وفي مجاالت حفر األنفاق يعمل المهندس الجيولوجي على إجراء التحريات الجيولوجية الالزمة ألجـل •ق آخذاً في عين االعتبار المشاكل المختلفة أثناء حفر األنفـاق وبعـدها وكـذا تحديد المسار الدقيق للنف

. التكاليف اإلقتصادية إلجراء عمليات الحفر والبناء

وفي مجال إنشاء الطرق والجسور فإن المهندس الجيولوجي يعمل على تخطيط الطرق علـى الخـرائط •لصخور التي تمر عليها الطرقـات وأسـلوب والكشف على ا, الجيولوجية والجغرافية والصور الجوية

معالجة كل مرحلة إنشاء وتحديد مواقع المواد المطلوبة لإلستخدام في مجال رصف الطرق وذلك ضمن . التحريات الجيولوجية التي يقوم بها

وفي مجال الزراعة والري يعمل المهندس الجيولوجي على معرفة أنواع التربـة وتركيبهـا وصـدرها • . الزراعية كتشاف مصادر المياه الجوفية وإنشاء السدود والقنواتوخصائصها وا

ان المهندس الجيولوجي يعمل على تقديم المعلومات الجيولوجية ألعماق مختلفة حسب الحاجة و يختبر نـوع ت التكونات الجيولوجية و المياه الجوفية و منسوبها و تحديد مكوناتها الكيميائية في مشاريع التاسيس للمنشـآ

ألجل الحصـول علـى GISلذلك فانه يقوم باستخدام احدث تقنيات ).السبخات(المدنية وخاصة للتربة المالحة المعلومات الالزمة لتفادي المشاكل الهندسية المتوقعة و تحديد مواقعها


١١

الخارطةتعريف

-:ء أشيا ٣هي عبارة عن رسم يحتوي على آثير من الرموز و األلوان و البد أن تحتوي على

N . إتجاه الشمال - ١ .مقياس الرسم - ٢ ) Legendمفتاح الخريطة (تعريف الرموز و األلوان - ٣

-:الخرائط الجغرافية • .لتحديد المناطق و المواقع و اليابس و الماء -

-:الخرائط الجيولوجية •

تجاه و طول و نوع الحرآات البنائية لتحديد مناطق وحدود و أنواع الصخور و التربة و إ - .و تعتمد على الوصف إما بالرموز أو األلوان . و الشقوق و الصدوع


١٢

أنواع الخرائط (Geographic Maps )الخرائط الجغرافية -١

.تهتم بالتضاريس واألبعاد وأشكال سطح األرض ( Contour Maps )الخرائط الكنتورية -٢

.تهتم باالرتفاعات واألبعاد الثالثة (Topographic Maps ) الخرائط الطبوغرافية -٣

.وهى خرائط الظواهر التضاريسية من جبال وانهار وقيعان بحار و أودية وسهول (Geologic Maps )الخرائط الجيولوجية -٤

ابقة وال ثالث معلومات الس ى المعلومات ال وي عل ة وهي خرائط تحت ة والبنائي تراآيب الجيولوجي .وأنواع التربة والصخور

(Engineering Geological Maps ) الخرائط الجيولوجية الهندسية -٥

ات ية ومعلوم ة و تضاريس ة وطوغرافي ة وآنتوري ات جغرافي ى معلوم وى عل رائط تحت ى خ وهام ب النظ خور حس ة والص ية لترب واص الهندس وز والخ ى رم الوة عل ة ع وب جيولوجي المطل

.استخدام خواصه والمعتمد عالميا (Geohazard Maps ) خرائط المخاطر -٦

دة ا ش وع وتصنيف الخطر إم ا حدود ون ة موضح عليه ة وطبوغرافي ارة عن خرائط جغرافي عبوط ات هب ا نطاق ة زام الهزات وإما شدة البراآين وإما حدود مجرى سيل وإما تجمع الكثبان الرملي

طاقات االنزالقات األرض وإما ن .األرضية


١٣

الخرائط الجيولوجية الهندسيةEngineering Geological Maps

(Engineering Geological Maps ) الخرائط الجيولوجية الهندسية

ى ة وعل ى معلومات جعرافي وى عل هى عبارة عن خرائط لها حدود وأبعاد ولها مقاس رسم وتحتي ا ة ف دود آنتوري ات ح ى معلوم طح األرض وعل اريس لس ات والتض ات واالنخفاض الرتفاع

ات ل الصدوع والطي ة مث ة البنائي ب الجيولوجي ى تراآي ة وعل ات التجوي واع الصخور ودرج ألن .والتشققات والتشوهات

ل تخدم لعم ام المس ب النظ ية حس ائص الهندس ي الخص دة ف وز المعتم ص لرم افة لمخل باإلض

ن نظ ف م ات وتختل ل النطاق ة لعم وز مهم ذه الرم ة وه واء الصخور او الترب ام س ى نظ ام إلZoning ) ( الذى هو اساس رسم الخرائط الجيولوجية الهندسية.

-:الخرائط الجيولوجية الهندسية

عبارة عن رسم يحتوي على الظواهر الجغرافية و الظواهر الجيولوجية و على رموز و قيم تعبر عن .ونات الجيولوجية سواءا التربة أو الصخور الخواص الهندسية للمتك

.و تصنف إلى ثالث أصناف و .يجب أن تكون على أساس خارطة جيولوجية سليمة يوضع عليها الخواص الهندسية الجيولوجية

هي خرائط لها حدود وأبعاد ومقياس رسم وتحتوي على معلومات جغرافية وعلى حدود آنتورية في وأنواع الصخور ودرجات التجوية وعلى , ت وعلى تضاريس سطح األرض االرتفاعات واالنخفاضا

باإلضافة إلى ملخص للرموز المعتمدة في .التراآيب الجيولوجية البنائية مثل الصدوع والفوالقوتختلف من نظام إلى نظام سواء .الخصائص الهندسية حسب النظام المستخدم لعمل النطاقات

الذي هو أساس رسم الخرائط ) zoning(ز مهمة لعمل النطاقات وهذه الرمو, للصخر أو التربة .الجيولوجية الهندسية

)الخرائط الجيولوجية الهندسيةوتعتبر من ( -:خرائط المخاطر الجيولوجية •

ى - عبارة عن خرائط جيولوجية هندسية تحتوي ظواهر جغرافية و متكونات جيولوجية و علواص الهندس ن الخ ر ع يم تعب وز و ق ات رم ا معلوم ع مضاف إليه ي الموق اطر ف ية للمخ

ة و ان الرملي ات الكثب ن متكون ية و ع زات األرض ن اله ات ع ة و معلوم هيدروجيولوجي .اإلنهيارت الصخرية حسب الخارطة المطلوبة


١٤

الجيولوجية الهندسيةتصنيف الخرائط

Classification of Engineering Geological Maps :- a- Based on Scale:- الخرائط المعتمدة على مقياس الرسم

.العالقة بين المسافات في الطبيعة و المسافات في الخارطة -1- Large Scale:-

1: 100,000 ……. 1: 1,000,000 > 2- Medium Scale:- 1 : 10,000 – 1 : 100.000 1 cm : 100000 cm

الخارطة الطبيعة 3- Small Scale :- 1 : 10.000 and less 1 cm = 1000 cm

الطبيعة الخارطة 1 cm = 100 m

b- Based on Purpose

.الغرض أو الهدف الخرائط المعتمدة على -1- Special purpose Map:-

.خرائط ذات هدف أو غرض معين -

- Small Scale Map. - Large Scale Map. - Analytical map.

2- Multi – purpose Map:-

.خرائط ذات أهداف أو أغراض عديدة -- Comprehensive map.

c- Based on Content: - الخرائط المعتمدة على المحتوي 1- Analytical Map. 2- Comprehensive.


١٥

Engineering Geological Maps )الخرائط الجيولوجية الهندسية (

وهى تشمل الظواهر الجيولوجية والطبوغرافية والجغرافية والجيوموفولوجية باالظافة الى رسم الخواص الهندسية لكل من أنواع الصخور

ماهى انواع الخرائط الجيولوجية الهندسية Classification of Engineering Geological Maps

1- Based on Scale

a- Large Scale Map (1:1000000-1:100000) b- Medium Scale Map (1:100000-10000) c- Small Scale Map <10000

2- Based on Purpose ويعتمد على نوع المعلومة2.1- Special Purpose 2.1- Multi Purpose

3- Based on Content ويعتمد على المحتوي

3.1 Analytical Map 3.2 Comprehensive

( Zoning ) ماهو النطاق

هى مواقع على الطبيعة ام الودية او لجبال يتم فيها توحيد وجمع وربط المواقع التي تتشـابهة فـي الخواص الهندسـية نوع الصخر ودرجة التجويه وفي الرموز الموحدة والمعتمدة لتصنيف ووصف

.وربط المواقع مع بعضها البعض

.الفرق بين الوصف والتصنيف التصنيف هو تحويل قيم الخواص إلى معايير رقمية ثم يتم جمع هذه المعايير للخروج برقم نهـائي

إما الوصف فهـو تحويـل قـيم . وينتهي بوصف مجموع قيم المعايير RMRموحد لتصنيف مثل الستخدامها فـي عمـل BGDمثل (Symbols )ل نظام وصفى إلى رموز الخواص الهندسية لك

.النطاقات ورسم الخرائط الجيولوجية الهندسية

-:الفرق بين التصنيف والوصف (classification )التصنيف

تحويل قيم الخواص إلى معايير رقمية ثم يتم جمع هذه المعايير بالخروج برقم نهائي موحد للتصنيف ). موحدة(بوصف لمجموع قيم معيارية وينتهي

Description )(الوصف تحول قيم الخواص الهندسية لكل نظام وصفي إلى رموز ووصف الستخدامه في عمـل النطاقـات

. ورسم الخرائط الجيولوجية الهندسية


١٦

مثال

Example of Description BGD

1-Rock Name

L 2- Layer Thickness

F 3- Fracture Intercept

S 4-Uniaxial Compressive Strength

A 5- Friction Angle

Classification Example of

RMR مثال على

Rating

٢٠ UCU

٢٠ RQD

١٥ j.S

٣٠ Joint Condition

٥ Ground Water

Total RMR =90


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A- Soil and Rock Description classification system For Engineering Purposes

1- Soil Description and classification system

Unified Soil Classification System (U S C S) BY: Terzaghi and peck 1968 Engineering proper ties of (U S C S) 1. Soil type 2. Grain size 3. Soil texture 4. Soil color 5. Cc _Cu 6. Strength 7. LL _PL

2- Rock description and classification Systems

B- Soil and Rock Mass Description and classification system For Engineering Geological Mapping

Rock and soil description and classification for engineering geological mapping. Bulletin of the International Association of Engineering Geology, No. 24, pp. 235-244.

classification Description a- Rock Mass Rating (RMR)

1974 Bieniawski: BY

1. Strength 2.Rock Quality Designation (RQD) 3. Spacing of Joint (J.S)4. condition of Discontinuity5. ground water

b- Rock Mass Description of Engineering purposeBY: Engineering Group Geological Society (GS) 1972

a- Basic Geotechnical Description of Rock Masses (BGD) BY: International Society of Rock Mechanics (ISRM) 1981 1. Rock name2. Layer thickness (L)3. Fracture intercepts (F) 4. Uniaxial Compressive Strength (UCS)5. Angle of friction(A)

Discontinuity1. type2. sets no3. Joint spacing4. orientation Dip / Dip direction

Rock material1. Rock type2. Color3. Grain size4. Strength


١٨

Soil Classification and Description

Soil Description :- 1- Soil Type . 2- Soil Color . 3- Mineral Composition . 4- Strength (Consistency) , Density .

Type of Soils :- 1- Sand . , 2- Silt . 3- Clay . 4- Sabkhah . 5- Mixed (Gravel, Sand, Silt, Clay)

-:مثال لبعض ألوان التربة و معرفة ترآيبها المعدني * - Yellowish Red (Granite : Mineral Composition : K- feldspar – Plagioclase) - Black – Gray (Diorite – Gabbro : Mineral Composition : Biotite – Muscovite) - Yellow – Beige (Clay – Dolomite)

: و مثال لتصنيفها SW , SP , CL

4- SPT (Standard Penetration Test) :-

N - Very Dense.

- Dense. - Medium Dense.

- Loose. - Very Loose.

• Soil Description :- مثال للوصف:- - Sand = Yellow. Dense, Angular, Very Loose. SW 0 – 15 % Relative Density.

ASTM (1985a). Standard practice for description and identification of soils (visual-manual) procedure. Test designation D2488-84. 1985 Annual Book of ASTM Standards, American Society of Testing and Materials, Philadelphia, Vol.04.08, pp. 409-423. ASTM (1985b). Standard test method for classification of soils for engineering purposes. Test Designation D2487-83. 1985 Annual Book of ASTM Standards, American Society of Testing and Materials, Philadelphia, Vol. 04.08, pp. 395-408.


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Soil Description

The sequence of describing a soil sample is as follows: a) Compactness and consistency b) Color c) Descriptive term d) Soil identification (Major constituents) e) Soil identification (Minor constituents) f) Water content descriptive term. a) Compactness and consistency: (stiffness or density) b) Color: the soil colors provide information of soil minerals and

environments.

• Red: Indicates iron oxide • Pale Yellow: Hydrated iron oxide • Black: Organic soils • Dark brown: due to dark • Gray: (manganese, magnetite) • Green: Glauconitic • White: Silica, gypsum, kaoline clay.

In general use only basic colors. Describe soils with different shades of basic colors by using two basic colors; e.g. Gray brown. “Mottled” means marked with spots of color while "streaked" means having color patterns which cannot be considered spotted. c)Descriptive term:

• Coarse grained soils i. Use angular, subangular, rounded etc. to indicate the shape of the

grains ii. Use coarse medium, fine, coarse to fine, or medium to fine to

indicate grain size distribution of the samples.

• Fine grained soils Use brittle, friable, spongy, sticky, fissured, fibrous, etc. if applicable.


٢٠

• Other descriptive terms applicable to both fine grained and coarse grained soils are : with occasional, with frequent, pockets of, layers of, seams of, lenses of, etc.

These will follow the soil identification. d) Soils identification: (Major constituents) Identify the major matrix of the soil sample and write this in Capital letters e.g. GRAVEL, SAND, SILT, CLAY. e) Soils identification: (Minor constituents) Identify the minor matrix of the soil sample and write this in small letters e.g. gravely , Sandy, Silty , Clayey. f) Water content descriptive term. Seepage, Wet, Dump, Dry, very Dry Examples: Sand : Dense, brown, subangular medium grained, trace silt, with pockets

of clay. Gravel : Very dense, gary, angular fine grained, some sand and trace silt,

with seems of clay. Silty Sand : Medium dense, gray brown, subrounded medium grained

with trace gravel and lenses of clay clay : Stiff, dark gray, sticky with some silt.

Soil Classification:

Unified Soil Classification System BY: Terzaghi and peck 1968

It includes:- 1. Soil type , 2. Grain size, 3. Soil texture, 4. Soil color, 5. Cc, Cu 6. Strength, 7. LL -PL Sieve analysis test is a test to determine gradation, which is common mean for describing the particle size distribution present in a soil. It is applied to the soil fraction consisting of gravel, sand, silt, and clay particles.

Soil Types:- (1) Cohesion:- CLAY (2) Cohesionless:- GRAVEL, SAND, SILT

Cu Coefficient of uniformity = D60 / D10 Cc Coefficient of curvature = (D30)2 / (D10*D60) Soil Strength :- The Standard Penetration Test (SPT) is useful in determining certain properties of soils, particularly of cohesionless soils, for which undisturbed samples are not easily obtained. SPT (Standard Penetration Test) :-Very Dense, Dense, Medium Dense. Loose Very Loose. Plastic Limit, PL, and Liquid Limit, LL are engineering properties for clays.


٢١


٢٢

Rock Mass Description

.الغرض هو رسم الخرائط الجيولوجية الهندسية - .و هو عبارة عن وصف آتابي - - :ويوجد نوعين من أنظمة الوصف -

1- Basic Geotechnical Description (BGD)

ISRM 1981

و أساسها لمهندسين التعدين

echanics .Mk ocRociety for Snternational I: ISRM

2- Rock Mass Description for Engineering Purposes (GS)

Geological Society 1972 – 1977 G

و أساسها جيولوجي


٢٣

Basic Geotechnical Description, (BGD) ISRM (1981)

- :و تعتمد على الخواص التالية I Geological factors: 1- Rock name. 2- Weathering .

II Structure Geology factors: 3- F.I. , J.S. 4- Layer thickness.

III Engineering factors: 5- Strength Parameters. 6- Friction Angle.

Basic Geotechnical Description of Rock Masses, Int. Rock Mech. & Min. Sci. & Geomech. Abst. Vol. 18, pp. 85-110, Pergamon Press Ltd., 1981.

و تحسب هذه الخواص و تنظم في جدول يحتوي على رقم الموقع و بالترتيب ذآر تحليل هذه

.الخواص لكل موقع و تحديد النطاق لهذا الموقع .و في التصنيف يجب ذآر المصدر الذي أخذ منه

:مثال


٢٤

St. 1 St. 2 St. 3 St. 4

Location Station :- بإسم الصخور و درجة التجوية و يوجد لدينا في هذا المثال اربع محطات يحدد. Location :- يحدد داخل المحطات ألخذ القراءات الهندسية أو قياسها و لدينا في هذا المثال.عشرة مواقع

نتائج خالصة ال Summary Results

Station No.

Rock Name

Weathering F.I , J.S.

Layer thickness

UCS ø Description

Zone

1 I 2 II 3 III 4 IIII

يتم عمل ورقة وصف لكل موقع و جدول لكل محطة يحتوي على عدد المواقع و اخر خانة

.للمتوسط : الحظة م

.إذا اتحد نوع الصخر و درجة التجوية و الرموز للخواص الهندسية نضعها في نطاق واحد

:مثال للوصف Granite: - W3 , F3 , L3 , S2 , A2 .

St. 1 : Granite , W3 , Location : 1.1 , 1.2 , 1.3 St. 2 : Basalt , W1 , Location : 2.1 , 2.2 , 2.3 , 2.4

St. 3 : Diorite , W2 , Location : 3.1

St. 4 : Diorite , W4 , Location : 4.1 , 4.2


٢٥

The description of rock masses for engineering purposes By

Geological Society (GS)

[ Engineering Group] Working Party .

:الخواص التي يعتمد عليها هذا التصنيف By the Geological Society (Gs)(Engineering Group) Working

Party, 1977

Intact Rock Properties of :Description

Rock Mass Properties of :Description

1‐ Rock type 2‐ Color 3‐ Grain size 4‐ Texture and fabric 5‐ Weathered and altered

state 6‐ Strength

1‐ Types2‐ Numbers of

discontinuity sets 3‐ Location and orientation4‐ Spacing between

adjacent discontinuities 5‐ Aperture of

discontinuity surface 6‐ Infilling 7‐ Persistence or extent 8‐ Nature of surface

Geological Society (1972). The preparation of maps and plans in terms of engineering geology. Geological Society Engineering Group Working Party Report, Quarterly Journal of Engineering Geology, Vol.5, pp. 295-381. Geological Society (1977). The description of rock masses for engineering purposes. Geological Society Engineering Group Working Party Report, Quarterly Journal of Engineering Geology, Vol.10, pp. 355-

. و بعد إيجاد الخواص السابقة و ترتيبها في جدول توصف في وصف آتابي


٢٦

Rock Mass Rating (RMR) 1974 Bieniawski: BY

نظام التصنيف بدال من نظام الوصف في عمل و رسم الخرائط الجيولوجية و يمكن إستخدام

.الهندسية و أآثر ما يستخدمه المهندسين النهم يهتمون بالقيمة اآثر من الخواص الجيولوجية

RMR Classification System /مثال

Rating

15 130 MPa UCS 17 75 % RQD 20 2 m J.S. .Joint con شرح 3010 Dry Ground Water

92 % ∑

RMR Classification (I) : - Very good Rock Mass .

.و يستخدم للمشاريع و األغراض الخاصة


٢٧

: أما رسم الخرائط الجيولوجية الهندسية بنظام التصنيف فالخريطة تكون بهذا الشكل

-:مالحظة

.جيولوجية الهندسية يتطلب عمل فحص للموقع لكي يتم عنل الخريطة ال Soil and Rock Description ٨٠مع تقدم العلم تدخل الجيولوجي الهندسي بنسبة % Soil and Rock Classification ٢٠تعتبر هندسية و يتدخل بها الجيولوجي الهندسي بنسبة %

. م ٢٠٠٤ام و هي طريقة جديدة في عمل الخرائط و قد تم العمل بها في ع

:و التصنيف المتبع في هذه الطريقة هو تصنيف RMR

.و منه يتم عمل نطاقات و من ثم رسم الخريطة الجيولوجية الهندسية

.و البيانات موحده في آل من الوصف و التصنيف

:و في تصنيف RMR

: يمكن رسم خريطة جيولوجية هندسية للمشاريع التالية Slope. Foundations Dam . Tunnels.


٢٨

Rock and soil description and classification for engineering

geological mapping

IAEG (1981). Rock and soil description and classification for engineering geological mapping. Bulletin of the International Association of Engineering Geology, No. 24, pp. 235-244.

- :أول ما يتم عمله من قبل الجيولوجي الهندسي .الخروج للموقع و فحصه - ١ .اإلآتشاف و التقييم و إجراء التجارب الحقلية و المعملية - ٢ .تعيين المخاطر و تحديد النطاقات ورسم الخرائط الجيولوجية الهندسية و من ثم آتابة التقرير - ٣


٢٩

Material Improvement

The soil and rock improvement will include two parts;

(A) Grouting, and (B) Deep Compaction.

A) Grouting

A.1 Definition:

Injection of fluid material under pressure to improve the geotechnical character of soil and rocks and to stop or reduce water movement. Grouting is expensive and time consuming process. A.2 Purpose: Grout are used to

1. improve the quality of soil and rocks in dams, tunnel, slopes, mines and foundation. The main purpose are:

2. increase the strength by cementing the particles (cohesion) 3. prevent water by reduce pore water pressure and reduce permeability 4. stop water leakage

A.3 Types of Grout:

a) Particles suspensions Clay grout: clay mixed with water to form colloidal Suspension. The clay may be bentonite. the strength is low reduce the permeability Clay and cement grout

to increase the strength keeping the permeability low

Cement grout: the cement water ratio is 3 to 5 to prevent clogging the pores. Bitumen: cheap grout used mainly for water stop.

b) Grout admixture : Some of the grouts are a mixture of more than one type to improve the grout quality (Table 1).

Table 1: The properties of some grout admixture

•


٣٠

Chemical c) There are grout: hundred of chemical grouts in the form of powder. The material is mixed with water in the site. The amount of powder added to water controls the setting

time. The chemical composition is presented in Table 2.

Table 2: The chemical grout

A.4 Site Investigation:

Grout that accelerate setting time

• Cacl2

• NaOH

• Sodium silicate Grout that reduce setting time

• Gypsum

• lime

Grout that increase plasticity and reduce shrinkage very fine bentonite (volcanic clay)

Silicate gel

Resins (Acrylic and Phenolic)

Phenol-formaldehyde Acrylate Resorcinol-

formaldehyde Polyacrylamide Foam Am-9 DMAPN Cemex-A


٣١

1. Geology Rocks: look for fissures, faults, or weakness zones (shear zones)

Soils: Soil type and permeability

2. Geotechnical survey:

2.1 Drilling to discover the soil/rock types and boundaries. 2.2 Soil properties (k) 2.2.1 Permeability: This will tell us how easy the grouting fluid can penetrate.

Should be determined in boreholes "site"

k =(Q)/ 5.5 r H

Q = volume of flow r = radius of casing H = differential head causing flow

2.2.2 Porosity: It gives an indication of the volume required to fill the soil (rock) with grout fluid.

2.2.3 Borehole size distribution i. if 20% passes # 200 grouting is not successful ii. grout particles < (1/10) D50

2.2.4 Pore size distribution

Grout particles = soil pore size

A.5 Grout selection:

The correct grout for a given project is selected based on:

The purpose (strength and/or water tightening)

The purpose (strength and/or water tightening) The material to be treated (soil or rock)

Look Table 7-4 and Table 7-17. The grout viscosity

The grout grain size

The availability in local market

The setting time

The grout price (Table 7-16).


٣٢

Example (1): If the ground k-value is 5x10-3 m/s. What is the grout type if it the purpose is to increase strength. The selection of grout material based on (Figure 5.5):

(1) Purpose. (2) material to be treated (soil). (3) Permeability. Answer : the grout is Asphalt Emulsion

Fig. 5-5. Grout applications in loose soil.

A.6 Ground Treatment: Following the selection of the grout type and ground, the area to be treated should be estimated (in square meters) and the depth of the treatment. Grouting is conducted in the following steps; Select the suitable grout type based on the properties and condition of the ground to be treated (Figure 5.5, Table 7.4, Tables 4.1-4.2 ). Check again the grout suitability based on prices (Tables 7-16). The grout is injected to the ground inside drill holes. The standard of the boreholes is shown in Figure 7.39. The depth of the drilling depends on the thickness of the layer to be treated (5 or 10 m deep).

The spacing of the drill holes depends on the type of ground material, soil or rock (Table 7.9). The volume of the grout depends on the porosity of soil ( !) or the estimation of the fracture size in rocks. Example (2): Fine sand under a dam is to be treated to increase the


٣٣

strength. The ground surface area is 55 by 25 m, and treatment should be to a depth of 5 m. The soil permeability

(k) is 5x10 m/s. The soil porosity (n) is 0.25. The cost of cement is SR 60 per m3, the relative cost of the grout to be used is 1.5. Determine

• The grout type to be used • The volume of the grout • The total cost of the grout

Solution

(1) Use Figure 5.5 to determine the grout type based on k value and purpose (strengthening). ..... the suitable grout is Silicate gel (for strengthening).

(2) The volume of the treated soil is 55x25x5 m3 ( 6,875 m3). The volume of the grout depend on the soil porosity (n=0.25), then the volume of the grout (Vg ) is

Vg . 6,875 x 0.25 = 1,718.75 m3

(3) The total grout cost can be estimated as follow: - the grout volume is 1,718.75 m3 - the cost of cement is SR 60 per m3, which means that if the used grout was cement then it cost : 60 x 1,718 = SR 103,125 (But remember that we did not use cement). - the selected grout relative cost is 1.5, then the cost of the selected grout is:

103,125 x 1.5 = SR 54,687.5


٣٤

B) Deep Compaction: This method is restricted to soil only. The main types of deep compaction are;

B-1 Static Compaction

B-2 Dynamic compaction

B-3 Vibrofloatation

B-4 Deep blasting

B-1

Static Compaction

This method is slowing arid used for fine grained soil (silt and clay). Large and heavy rectangular concrete are placed on the soil for months and the soil settlement is monitored.


٣٥

B-2 Dynamic compaction (Menard, 1972)

Weight of bounder (Wx) = 5 to 40 tons Dropping height (hx) = 10 to 40 m Energy = 4000 ft-ton Crater depth 1 to 3 m Effective depth (De) can be calculated from;

De = (Wx hx)'/2

The average De is about 10 to 15 m

B-3 Vibrofloatation

Good for loose granular soils by rearranging loose cohesionless grains into denser array (Figure 4.5). It is more suitable where explosions can not be used.

The degree of suitability depends on the soil PI as follow;

Degree of suitability PI

Good to excellent 0 Fair to good 0 to less than 8 Not suitable more than 8

B- 4 Deep blasting


٣٦

Explosive compaction is carried out by setting off explosive charges in the ground. The energy released causes liquefaction of the soil close to the blast point and causes cyclic straining of the soil. This cyclic strain process increases pore water pressures and provided strain amplitudes and numbers of cycles of straining are sufficient, the soil mass liquefies (i.e. pore water pressures are temporarily elevated to the effective vertical overburden stress in the soil mass so that a heavy fluid is created). Experience has indicated that the degree of ground improvement obtained by blasting depends on the initial density of the granular subsoils. The density of loose deposits can typically increase considerably to relative densities in the range of 70 to 80%, whereas soils with initial relative densities of 60 to 70% can only be densified by a small amount. Our experience also indicates that EC generally causes volume changes equal to or in excess of what would be anticipated under design levels of earthquake shaking, as described in the attached reference paper by Gohl et al (2000).

The radius of the effected area (r) is:

r = (w)1/3 C

where r = radial distance w = charge weight of explosive C = charge factor depending on the soil type

Example: if Wt 6 x 1.2 kg charge Depth 7 m Soil is loose sand ------ this will give

Settlement of 0.4 m and 10 m effective depth


٣٧


٣٨

IMPROVEMENT TECHNIQUES

1. Compaction.

2. Dewatering.

3. Stress and Settlement.

4. Foundations.

5. Pilings


٣٩

1.Compaction Soil is extensively used as a basic material of construction. For example: dams, dikes, embankments, ramps, etc. The advantages of using soil are that it (1) is generally available everywhere, (2) is durable – it will last a long time, and (3) has a comparatively low cost.

It is typically placed in layers (sometimes called lifts) with each layer being compacted to develop a final elevation and/or shape.

Why Does It Need Compacted?

Compaction increases a soils density. This produces the following effects: 1. increases the soil’s shear strength 2. decreases future settlement 3. decreases the soil’s permeability (also a function of soil type) 4. stable against volume change as water content or other factors change 5. relatively durable and safe against deterioration

It is most appropriate to talk about a compaction energy. The compaction energy given to a soil is proportional to the pressure, speed of rolling, and the number of times it is rolled. A unique aspect of soil is encountered when one wants to maximize the density but minimize the compaction energy – which makes good business sense. For a given compaction energy, there is an optimum water content that will obtain a maximum dry density. Too little or too much water content will cause a smaller dry density. The water acts as a lubricant and allows the soil particles to squeeze together more easily.

The Standard Proctor Test is a laboratory test used to determine the optimum water for a given compaction energy, for a given soil. The graph below illustrate the results obtained from a Standard Proctor test:

Quick glance at the Standard Proctor test procedures (ASTM D 1557): (1) dry sample until friable (easily crumbled) with trowel (2) prepare at least 4 samples using the same soil but different moisture contents (3) wait for a specified curing time (4) compact (gives a standard energy/vol) (5) measure γ and ω.


٤٠

Types of compactors (machine images courtesy of Bomag GmbH)

Error!

Hand Compactor(motorized

and non-motorized)

Error!

Walk Behind Roller

Error!

Walk Behind

Vibratory Plate

Error!

Walk Behind Double Smooth

Roller

Error!

Towed Single Roller

(Vibratory or non-vibratory)

Error!

Error!

Smooth Roller

(Many times vibratory)

Error!

Smooth Roller

Error!

Pneumatic Roller (smooth

rubber tires)

Error!

“Sheepsfoot”

(Protrusions stick out

from smooth

roller, can supply

pressures in excess of

600 psi or 4200

kN/m2)

Error!

Grader (Not a compactor,

but often used in conjunction with

compactors)

Error!

Error!

Heavy Compactor/Bulldoz

er (also a “Sheepsfoot”

compactor)


٤١

Soil type, water content, and type of compactor are factors that need to be considered when compacting. Compaction is often used when fill (disturbed soil from another location and transported) is used at a construction site. This implies you may be using self-propelled scrapers (earth movers), bulldozers, and graders. An earthcut or “borrow” is popular to use. A borrow is simply a hole dug (usually near the construction site) so that soil from this hole is used elsewhere as fill.

Borrows and fill dirt being used at a construction site. Notice the darker top soil with the lighter subsoil.

Rules of Thumb For Compacting Soils: I. Granular soils can be compacted in thicker layers (or “lifts) than silt or clay. II. Fill placed underwater (or requiring good drainage properties) should consist of granular or coarse material. III. Check to make sure natural soil is adequate for supporting compacted fill. This can be tested by rolling over it with a heavy piece of equipment and observing compaction characteristics (called “proof-rolling”). IV. Cohesionless soils usually need kneading, tamping, vibratory compacting. (Note: kneading is defined as working by folding.) Cohesive soils usually need kneading, tamping, or impact. Heavy cohesive soils can sometimes require dynamic compacting that uses large weights dropped from heights or underground dynamite with directed explosions.

Compaction Control Field Testing: 1. Sand Cone – requires hole excavated, weigh the soil removed and determine the volume of the hole with sand. This is done by filling the hole with a sand of known density. 2. Washington Densometer – requires hole excavated 3. Oil Replacement – requires hole excavated, weigh the soil removed and determine the volume of the hole with a device with an expandable rubber membrane 4. Nuclear Densometer – uses a radioactive source and “counter” to determine soil density. This method has fast results with the potential for a large number of tests in a short time. It is usually calibrated with the Sand Cone method.


٤٢

Compaction Characteristics and Soil Grouping in USCS

Group Symbol Compaction Characteristics

Compressibility and Expansion

Value as Embankment

Material

Value as Subgrade Material

GW Good Very Little Very Stable Excellent

GP Good Very Little Reasonably Stable

Excellent to Good

GM Good Slight Reasonably Stable

Excellent to Good

GC Good Slight Reasonably Stable Good

SW Good Very Little Very Stable Good

SP Good Very Little Reasonably Stable when Dense

Good to Fair

SM Good Slight Reasonably Stable when Dense

Good to Fair

SC Good to Fair Slight to Medium

Reasonably Stable Good to Fair

ML Good to Poor Slight to Medium

Poor, gets better with high density

Fair to Poor

CL Good to Fair Medium Stable Fair to Poor OL, MH, CH, OH, PT Fair to Poor High Poor, Unstable Poor to Not

Suitable


٤٣

2. Dewatering

When soil is excavated below or near the water table, pumps will usually be used to dewater the site. This involves creating a drawdown curve (or cone of depression) that is below the base of the excavation. Factors that are important include soil permeability, depth of water table, depth (and geometry) of excavation.

Single stage dewatering

The above diagram illustrates a dewatering technique using small trenches dug around the perimeter of the excavation. One can estimate the pumping requirements based upon the formula

(reference: Soils In Construction, W.L. Schroeder, S.E. Dickenson, Prentice Hall 1996, pg. 162). The value D represents the radius of influence, H is the depth to an impermeable layer from the original water table, ht is the height of the water level in the interceptor ditch with respect to the impermeable layer, k is the soil’s permeability, and q is the pump per unit length of ditch. A more elaborate two-stage dewatering technique is shown in the diagram below.

Multi-stage dewatering


٤٤

As a general rule, when the excavation is deep (with respect to the water table) and the soil is very permeable (i.e. gravel or sand), a high pumping rate will be required. For an excavation that extends just slightly below the water table and the soil is somewhat impermeable (i.e. clay or silt), a lower pumping rate is required. Be careful, the depth of a water table varies as a function of time for any given site! This means that the depth of the water table varies with seasons or possibly local precipitation.

Drawdown curve for an excavation site with two pumps.


٤٥

3. Stress and Settlement

A strange case of Palace of Fine Arts in the Alameda area of Mexico City. Built sometime between 1900 and 1934, it was a magnificent and strongly built structure. It was built on grade, level with the square and other buildings nearby. But because of loose sand permeated with water in the subsurface, the massive structure sunk 6 ft into the ground! (Luckily, it settled evenly minimizing structural damage.) Believe it or not, in the 1960’s the building moved again. This time it moved 12 ft up! The weight of skyscrapers being built around the Palace had pushed the subsurface water and soil around sufficiently to raise the building.

(Source: Why Buildings Fall Down, M. Levy and M. Salvadori, WW Norton & Company, 1992)

The Milwaukee Metropolitan Sewerage District (MMSD) agreed to a $24 million settlement in a claim against the engineering firm CH2M Hill. MMSD claimed the engineering firm mis-judged the weak bedrock and potential for flooding in the designs of a 5.3-mile North Shore deep tunnel project. This project was designed to store raw sewage during rain-storms and snow melts, preventing the polluted water from fouling the area’s rivers and Lake Michigan. MMSD also agreed to pay $3.5 million to settle claims from downtown businesses. These businesses claimed water pouring into the tunnel drained ground water under downtown businesses, causing building foundations, walls, sidewalks and sewer connections to crack. (Source: Milwaukee Journal Sentinel, December 5, 1998)

Worlds oldest building code, the Code of Hammurabi.

Settlement and Consolidation of Soils

Any structure built on soil is subject to settlement. Some settlement is inevitable and, depending on the situation, some settlements are tolerable. When building structures on top of soils, one needs to have some knowledge of how settlement occurs and predict how much and how fast settlement will occur in a given situation.

Important factors that influence settlement:

• Soil Permeability • Soil Drainage • Load to be placed on the soil • History of loads placed upon the soil (normally or over-consolidated?) • Water Table

Settlement is caused both by soil compression and lateral yielding (movement of soil in the lateral direction) of the soils located under the loaded area. Cohesive soils usually settle from compression while cohesionless soils often settle from lateral yielding – however, both factors may play a role. Some other less common causes of settlement include dynamic forces, changes in the groundwater table, adjacent excavations, etc. Compressive deformation generally results from a reduction in the void volume, accompanied by the rearrangement of soil grains. The reduction in void volume and rearrangement of soil grains is a function of time. How these


٤٦

deformations develop with time depends on the type of soil and the strength of the externally applied load (or pressure). In soils of high permeability (e.g. coarse-grained soils), this process requires a short time interval for completion, and almost all settlement occurs by the time construction is complete. In low permeable soils (e.g. fine-grained soils) the process occurs very slowly. Thus, settlement takes place slowly and continues over a long period of time. In essence, a graph of the void ratio as a function of time for several different applied loads, provides an enormous amount of information about the settlement characteristics of a soil. Terminology Pressure (or load) is defined as the amount of weight being distributed over an

amount of area. Mathematically: . Overburden pressure is the effective pressure (sometimes referred to as effective weight) of the overlaying soil. This can be calculated according to the formula P=γh where γ is the unit weight of overlaying soil and h is the depth. Normally consolidated clay has never been subjected to any loading larger than the present effective overburden pressure. The height of the soil above the clay has been fairly constant through time. Overconsolidated clay has been subjected at some time to a loading greater than the present overburden pressure. This type of clay is generally less compressible. Coefficient of consolidation, cv, is a measure of how fast and how much a sample of soil will deform under a load. A large value indicates a fast consolidation and a low value indicates a slow consolidation. Estimating Settlement in Clay and Sand How fast does the soil settle? The process of obtaining a quantitative prediction of how much a soil will settle and how fast begins with examining a plot of soil deformation as a function of time for a given load. The soil deformation will correspond to a void ratio. Figure 1 shows such a plot.

Figure 1

Primary consolidation of the soil happens before point A on the graph.


٤٧

The secondary consolidation happens after point A and is characterized by a very slow settlement. The coefficient of consolidation, cv, for a particular loading is related to the shape of this graph and is defined as

(1) where H is the thickness of the test specimen at 50% consolidation, and t50 is the time to 50% consolidation. One can use this parameter to calculate the time rate of settlement with equation 2 and figure 2. The time, t, to reach a particular percent of consolidation is

(2) where H is the thickness of the consolidating layer, Tv is a time factor that depends of the percent consolidation and is obtained from figure 2, and cv is the coefficient of consolidation.

Figure 2

How much will the soil settle?

Figure 3


٤٨

Now, to calculate the total settlement due to primary consolidation, we need to introduce the equation (derived from figure 3):

(3) where S = total settlement due to primary consolidation, eo = initial void ratio of the soil in situ, e = void ratio of the soil when subjected to a total pressure (p), H = thickness of the consolidating clay layer (if the cohesive soil layer is underlain by sand and gravel then use ½H for the thickness and use H if underlain by bedrock) , p = total pressure acting at midheight of the consolidating layer, po = present effective overburden pressure at midheight of the consolidating layer. The constant Cc is the compression index and is equal to the slope of the curve indicated in figure 3. Its value can be calculated by

(4) with the variables defined the same as in equation 3. Example: Consider an 8 ft clay layer beneath a building that is overlain by a stratum of permeable sand and gravel and is underlain by impermeable bedrock. The total expected consolidation settlement for the clay layer due to the footing load is 2.5 in. It is also known from laboratory tests that cv=2.68x10-3 in.2/min.

Find: (1) How many years it will take for 90% of the total expected consolidation settlement to take place? (2) What amount of consolidation settlement will occur in 1 yr.?

(1) t = (Tv/cv)H2 Tv = 0.848 (using U = 90% in figure 2) H = 8ft(12in/1ft) = 96 in t90 = ( (0.848)(96in)2 )/(2.68x102 in2/min) = 2.9x106 min or 2.9x106 min (1hr/60min)(1d/24hr)(1yr/365d) = 5.5 years

(2) Work part one in reverse: t = (1yr)(365d/1yr)(24hr/1d)(60min/1hr) = 5.26x105 min Tv = (tcv)/H2 = ( (5.26x105 min)(2.69x10-3 in2/min) )/(96in)2 = 0.15 Tv = 0.15 corresponds to U = 43% (figure 2) Thus, S1yr = (2.5in)(0.43) = 1.08 in.

In sandy soils, settlement occurs fast (soil is usually settled before construction is done) and the amount of settlement is determined in a different way than cohesive soils. The maximum settlement on dry sand can be calculated by

where smax is the maximum settlement (inches), q is the applied pressure (tsf), B is the width of the footing, and Nlowest is a number of blows required to drive a rod while following a standard set of procedures. It should be noted that this equation has a correction factor if the groundwater table is close to the footing. Example of a settlement analysis with a high water table and multiple soil layers


٤٩

Time of Soil Settlement Animation Illustrates primary and secondary rates of consolidation.

Soil Compression Characteristics Animation Soil does not behave like a spring (i.e. it does not follow Hooke’s Law). Once compressed it rebounds only slightly upon un-loading. This animation demonstrates the different behavior for normally consolidated and over-consolidated soil.

Settlement cracks that have developed in the masonry near the the Stout physics department offices in Jarvis Hall.

Same crack line but on the opposite side of the wall. The crack goes right into the floor tiling.

Differential settlement of the Soil Retaining wall at UW-Stout during the summer of 2001.


٥٠

4. Foundations "On account of the fact that there is no glory attached to the foundations and that the sources of success or failure are hidden deep in the ground, building foundations have always been treated as step children and their acts of revenge for the lack of attention can be very embarrassing." Karl Terzaghi [source: Lundin, T., 2001, Are you saving nickels or dollars?, Hanson Insight newsletter, <http://www.hansonengineers.com/insight/0502/story4.htm>,

May] Important aspects to be aware of: I. In the design plans, the depth of the footings should be indicated with respect to the final grade around the house. Foundation footings should be no less than 4 feet deep (Wisconsin Standard) and should not be placed onto disturbed soil. The footings need to be below the frost line. The frost line is the depth to which soil freezes during the winter. The soil above the frost line is subject to large amounts of fost heaving and shrinking (when ice melts) and can cause extreme cracking for too shallow of foundations. II. Foundation footings should be placed upon good soil. This information can be obtained by soil exploration and laboratory testing. One could also ask neighbors about their foundations and the extent of cracking in their walls. III. The sewer pipe should enter the house below the footing (sometimes at a depth of 8 inches from the bottom of the footing to the top of the pipe). The sewer pipe should have a slope of about 1/8in. every foot causing contents to move away from the house. Bearing Capacity for Shallow Foundations Structure foundations are subject not only to settlement but also to shear failures. First of all, foundations usually have the design of an inverted T. Where columns or walls are resting on a footing and the footing has an enlarged area to reduce the pressure exerted on the soil for a given load. In general, foundations must be designed to satisfy the following criteria:

1. They must be located properly (both vertically and horizontally orientation) so as not to be adversely affected by outside influences.

2. They must be safe from excessive (or non-uniform) settlement.

3. They must be safe from bearing capacity failure (shear failure).

There are three modes of shear failure: general shear failure, local shear failure, and punching shear failure. These modes characterize the stress-strain dynamics that happen in certain soil types. General shear failure is identified by a well-defined wedge beneath the foundation and slip surfaces extending diagonally from the side edges of the footing downward through the soil, then upward to the ground surface. The ground surface adjacent to the footing bulges upward. Soil displacement is accompanied by tilting of the foundation (unless the foundation is restrained). The load-settlement curve for the general shear case indicates that failure is abrupt.


٥١

Punching shear failure involves significant compression of a wedge-shaped soil zone beneath the foundation and is accompanied by the occurrence of vertical shear beneath the edges of the foundation. The soil zones beyond the edges of the foundation a little affected, and no significant degree of bulging occurs. Aside from a large settlement, failure is not clearly recognized.

Local shear failure has elements of both general and punching shear failure. It has well-defined slip surfaces that fade into the soil mass beyond the edges of the foundation and do not carry upward to the ground surface. Slight bulging of the ground surface adjacent to the foundation does occur. Significant vertical compression takes place beneath the foundation.


٥٢

Terzaghi has developed a theory that predicts the ultimate bearing capacity a soil has in regards to shear failure. Before working with the formula’s, it is important to understand the terms "ultimate bearing capacity" (qult) and "allowable bearing capacity" (qa). The ultimate bearing capacity of a soil refers to the loading per unit area that will just cause shear failure in the soil. Allowable bearing capacity refers to the loading per unit area that the soil is able to support without unsafe movement. Such that, (qult) = (safety factor)x(qa). The formulas for calculating the qult are: Continuous Footings (width B):

qult = cNc + γDfNq + 0.5γBNγ Circular Footings (radius R):

qult = 1.2cNc + γDfNq + 0.6γRNγ Square Footings (width B):

qult =1.2cNc + γDfNq + 0.4γBNγ where qult = ultimate bearing capacity, c = cohesion of soil (measured with a shearvane - as a rule of thumb, the unconfined compressive strength is about twice the cohesion of the soil), γ = effective unit weight of soil, Df = depth of footing, or distance from ground surface to base of footing, B = width of continuous or square footing, R = radius of circular footing, Nc, Nγ, Nq = soil-bearing capacity factors, dimensionless terms, whose values relate to the angle of internal friction, ϕ. These values can be calculated when ϕ is known or they can be looked up in the table below. Nq = eπtanϕtan2(45o + ϕ/2) Nc = (Nq - 1)cot(ϕ) when ϕ > 0o or Nc =5.14 when ϕ = 0o. Nγ = 2(Nq + 1)tanϕ

ϕ Nc Nq Nγ

0 5.14 1.0 0

5 6.5 1.6 0.5

10 8.3 2.5 1.2

15 14.0 3.9 2.6

20 14.8 6.4 5.4

25 20.7 10.7 10.8

30 30.1 18.4 22.4

32 35.5 23.2 30.2

34 42.2 29.4 41.1

36 50.6 37.7 56.3

38 61.4 48.9 78.0


٥٣

40 75.3 64.2 109.4

42 93.7 85.4 155.6

44 118.4 115.3 224.6

46 152.1 158.5 330.4

48 199.3 222.3 496.0

50 266.9 319.1 762.9

As an example of using these equations, consider a strip of wall footing 3.5 ft wide and is being supported in a uniform deposit of stiff clay. The unconfined compressive strength (by a pocket penetrometer) of this soil is 2.8 kips/ft2 (1 kips = 1000 lbs). The unit weight is 130 lb/ft3. There was no groundwater encountered and the depth of the wall footing is 2 ft. Find the ultimate bearing capacity of this footing and the allowable wall load, using a factor of safety of 3.

Solution:

qult = cNc + γDfNq + 0.5γBNγ c~qu/2 = (2.8 kips/ft2)/2 = 1.4 kips/ft2 γ = 0.130 kips/ft3 Df = 2 ft B = 3.5 ft from the table above: Nc = 14.0, Nq = 3.9, Nγ = 2.6 Thus, qult = (1.4 kips/ft2)(14) + (0.130 kips/ft3)(2 ft)(3.9) + (0.5)(0.130 kips/ft3)(3.5 ft)(2.6) = 21.2 kips/ft2

qa = qult/3 = (21.2 kips/ft2)/3 = 7.1 kips/ft2 The Terzaghi equations above do not consider eccentric (torques or non-vertical forces) loads, inclined foundation base, or footings on or near slopes. The bearing capacity of footings placed into sloping ground is less than if the footings were on level ground. In fact, the bearing capacity of a footing is inversely proportional to ground slope. Modifications to the Terzaghi equations do exist and enable one to calculate the ultimate bearing capacity under eccentric loads, inclined foundations, and sloped ground.


٥٤

5. Pilings During the 1950's, a large hotel was to be built along the coast in Florida. After performing soil explorations, the geotechnical engineers recommended 30 ft long friction piles to support a 25 story hotel. During the last drop of a pile driver's weight, one of the piles disappeared! It had suddenly busted through to a very weakly supporting soil layer called "Florida pancake" that was not identified in original explorations. The piles had to be lengthened to 140 ft. (Source: Why Buildings Fall Down, M. Levy and M. Salvadori, WW Norton & Company, 1992) Pile and Caisson Foundations When an extended layer of soil is unsuitable to build upon because of bearing capacity failure or excessive settlement, a Pile or Caisson foundation can be used to support structures. These foundations are designed to transmit the load of a structure to firmer soil, or rock that exists deep below the structure. Pile foundations consists of a long and slender "member" that is forced or driven into the soil. It is driven until it rests on a hard, imprenetrable layer of soil or rock, the load of the structure is transmitted primarily axially through the pile. This type of pile is an end-bearing pile. If the pile cannot be driven to a hard stratum of soil or rock, the load of the structure must be borne primarily by skin friction or adhesion between the surface of the pile and adjacent soil. This is a friction pile. Piles can be made of timber, concrete (precast or cast-in-place), or steel (pipe-shaped or eye-beam shaped). Sometimes piles are a combination of these materials. Caisson foundations usually consist of a structural box or chamber that is sunk in place or built in place by systematically excavating below the bottom of the unit, which thereby descends to the final depth. The drilled caisson is another type (less extensive in scope than the box type) that is constructed by using an auger drill to forma hole in the soil in which concrete is eventually poured. Illustrations of different piling

I-Beam Piling

Concrete Bulb Piling Caisson

(material removed from inside)

Larger Shaft Caisson For Performing Work Within the Caisson


٥٥

Pile type

Description of use and availability

Range of Maximum

Load (KN)

Timber Depends on wood (tree) type. Lengths in the 50 to 60 ft range (15 to 18 m) are usually available in most areas; lengths to about 75 ft (25 m) are available but in limited quantity; lengths up to the 100 ft range (30 m) are available, but supply is very limited.

100-300

Steel H and pipe Unlimited length; "short" sections are driven and additional sections are field-welded to obtain a desired total length.

Steel shell, cast-in-place

Typically to between 100 and 125 ft (30 to 40 m), depending on shell type and manufacturer-contractor.

250- 700

Precast concrete Solid, small cross-section piles usually extend into the 50 – 60 ft length (15 to 18 m), depending on cross-section shape, dimensions, and manufacturer. Large-diameter cylinder piles can extend to about 200 ft long (60 m).

Drilled-shaft, cast-in-place concrete

Usually in the 50 – 70 ft range (15 to 25 m), depending on contractor equipment.

Bulb-type, cast-in-place concrete

Up to about 100 ft (30 m). 600-9000

Composite Related to available lengths of material in the different sections. If steel and thin-shell cast-in-place concrete are used, the length can be unlimited; if timber and thin-shell cast-in-place concrete are used, lengths can be on the order of 150 ft (45 m).

250- 600


٥٦

Engineering Geological Report

Engineering Geological Studies

A. Geological Study. B. Engineering Study.

مراحل الدراسة المثالية

Study Phases

1- Desk Study : ة ة و الجغرافي ارير الجيولوجي ع الخرائط و التق هو تجميع آل ما درس و آتب عن الموقع و تجمي

.و التخطيطات الهندسية

2- Reconnaissance of the area: ا في التخطيط جولة إستطالعية على الموقع لرؤية المظاهر الجيولوجية و الهندسية لإلستف ادة منه

.للمراحل الالحقة من مراحل الدراسة الجيولوجية

3- Field Studies : العمل الحقلي لتجميع المعلومات و هو يأخذ أطول زمن من العمل و هو (و هو صلب الموضوع

.يمكن أن يكون في دراسات جيوفيزيائية أو جيومورفولوجية -:احل الدراسة و يجب عمل جدول زمني لكل مرحلة من مر -

:مثال

البرنامج الزمني المهمة مالحظات 1- Desk Study. 15 Days الدراسات السابقة2- Reconnaissance Study. 2 Days 3- Field Studies. 2 or 30 or 45 or 100 Days


٥٧

متطلبات الدراسة الجيولوجية الهندسيةمتطلبات الدراسة الجيولوجية الهندسية

: عام. ١

مل الدراسة الجيولوجية الهندسية هو إن الغرض من ع الحصول على معلومات وافية عن جيولوجيا المنطقة •توضيح الخصائص الهندسية للصخور والكتل الصخرية إلستخدامها في تصـميم المشـاريع •

.الهندسية .ونبين هنا كيفية إجراء الدراسة الجيولوجية الهندسية وطريقة إعداد التقرير الخاص بها

:ل الدراسة الجيولوجية الهندسيةمراح. ٢

:يمكن تقسيم مراحل الجيولوجية الهندسية إلى ثالث مراحل رئيسية هي

ويتم خالل هذه المرحلة جمع المعلومات والتقارير والخرائط :مرحلة الدراسة المكتبية )١الجيولوجية المتوفرة لمنطقة المشروع لدراستها وتكوين فكرة عامـة عـن خصـائص

جيولوجية والهندسية لالستفاده منها في التخطيط للمراحل الالحقه من مراحـل المنطقة ال .الدراسة الجيولوجية

ويتم في هذه الدراسة القيام بزيارة لمنطقـة المشـروع :مرحلة الدراسة االستطالعية )٢

للتعرف على الخصائص الجيولوجية للمنكشفات الصخرية بصفه عامة وتحديد ما يلـزم .لية للدراسة التفصي

:وتتضمن القيام بما يلي :مرحلة الدراسة التفصيلية )٣

حسب طبيعة ) إذا لزم األمر(ويتم إجراء هذه الدراسة :عمل الدراسة الجيوفيزيائية )أ(

:الموقع والمشروع باستخدام الطرق السيزموجرافية مثل Refractive methods الطرق االنعكاسية • Resistivity methodsالمقاومة الكهربائية • Magnetic methodsالطرق المغناطيسية •

ويتم خالل هذه الدراسة تحديد طبيعـة :عمل الدراسة الحيوموروفولوجية ) ب(وشكل األرض لمنطقة الدراسة ووضعها على رسومات توضـيحية تبـين

.مناطق التصريف واالنهيارات الحقلية الالزمة لتحديد ويتم من خاللها إجراء التقصيات :التقصيات الحقلية ) ج(

خصائص الصخور والكتل الصخرية لمنطقة المشروع وفقاً للكتيب الخاص بوصف وتعدين الصخور والتربة ألغراض عمـل الخـرائط الجيولوجيـة

.الهندسية وكذلك وفقاً للوصف األساسي للكتل الصخرية


٥٨

صـول علـى ويتم إجراء التجارب المعملية الالزمـة للح :الفحص المعملي ) د(

ومـن أهـم . خواص الصخور الستخدامها في تصميم المشاريع الهندسية :التجارب المعملية ما يلي

1. Unconfined compression test

2. Triaxial compression test

3. Point-load strength test

4. Brazilian strength test

5. Specific gravity test

6. Permeability and porosity tests

7. Thin-section microscopy

8. Slake durability test


٥٩

RREEQQUUIIRREEMMEENNTTSS FFOORR CCOONNDDUUCCTTIINNGG TTHHEE EENNGGIINNEEEERRIINNGG

GGEEOOLLOOGGYY SSTTUUDDYY

1. GENERAL: This report illustrates how to conduct the engineering geology study and the

guidelines for preparing its report.

The purpose of making the engineering geology study is:-

1. To get a comprehensive information about the geology of the project area, and

2. To find the engineering properties of rocks and rock masses in order to use

them in the design of the engineering projects.

2. PHASES OF THE ENGINEERING GEOLGOICAL STUDY:

There are three main phases of the engineering geological study:

1. Desk studies: Collection of the available information about the area of the

project from the published reports, maps, and aerial photographs. This will give

a general picture of the features of the regional geological setting. Full use is

made of the collected information to be used in the following phases.

2. Reconnaissance of the area: This may be in the form of a field trip to the

site which can reveal information on the landforms, outcrops, and the patterns

of vegetation and drainage. This information will help for the planning of the

detailed site investigation phase.


٦٠

3. Detailed site investigation: it indicates the following:

3 (a). Geophysical study: It can be made (if necessary) depending on the type of

project and the region characteristics using the following geophysical

techniques:

* Refractive Methods

* Resistivity Methods

* Magnetic Methods

3 (b). Geomorphological study: The topography of the area of the project is

established and put on maps that illustrate the locations of drainage and

landslides areas.

3 (c). Field study: Field investigation is performed to determine the

characteristics of rocks and rock s masses in the project area. The description of

rock and rock masses should be made according to:-

• Rock and Soil Description and Classification for Engineering Geological

Mapping

• Basic Geotechnical Description of Rock Masses .

3 (d). Laboratory tests: For each specific project, the required laboratory tests

should be conducted. The laboratory tests are likely to include, but not limited

to, most of the following:

* Unconfined compression test

* Triaxial compression test

* Point-load strength test

* Brazilian strength test

* Specific gravity test

* Permeability and porosity test

* Thin-section microscopy

* Slake durability test


٦١

التقرير الجيولوجي الهندسي . ٣

يجب أن يشتمل التقرير الجيولوجي الهندسي على بيان تفصيلي لجميع مراحل الدراسة الجيولوجية :الهندسية المذكوره سابقاً مع التركيز على ما يلي

:مقدمة . أ

.وصف المشروع .الغرض من الدراسة ).إن وجدت(استخدامات األراضي الخرائط الجيولوجية أو الخرائط الطبوغرافية أو

:الجيولوجيا الجيومورفولوجي . ب

.في الكتل الصخرية المؤثرةوصف للمتكونات الصخرية والتراكيب .نوعية الترسبات السطحية وسماكاتها .الخرائط الجيولوجية الهامة لرسم الخرائط الجيولوجية الهندسية والتعريـة، الفواصـل الصـخرية المنكشفات الصخرية من حيث نوع الصخر، التجويـة

.وخصائصها )الوصف الجيولوجي الهندسي: ( نطاق العمل. ج

:ويشمل ما يلي وصف الصخور من حيث النوع، والتركيب المعدني، وقوة التماسك، التجارب الحقلية

.والمعملية التي تم إجراؤها لتحديد هذه الخواص :وصف الكتل الصخرية وتحديد خصائصها التالية للفواصل ومستويات التطبـق ) Dip and Dip Direction( االتجاهقيمة زاوية الميل و

.والتشققات الصخرية )Layer thickness( سمك الطبقات الصخرية )Fracture intercept( تقاطع التشققات )Uniaxial compressive strength( قوة االنضغاط األحادي )Angle of internal friction( زاوية االحتكاك الداخلي )Joint spacing( المسافة بين الفواصل )Joint roughness( خشونة سطح الفواصل )Aperture( اتساع الفتحات )Infilling materials( المواد المعبئة للفواصل )RQD( معيار جودة الصخر .تحديد منسوب المياه الجوفية


٦٢

:النتائج والتحليل . د

الحقلية والمعملية بشكل مفصل وتحليلها للحصول علـى القـيم الهندسـية توضيح نتائج التجارب الالزمة لتحديد ثبات واستقرار الميول والحفريات سطحية مثل األنفـاق وغيرهـا مـن األعمـال الجيولوجية األخرى، ووضعها بصيغتها النهائية على خرائط جيولوجية هندسية لتمكن المهندس من

.هندسيةالقيام بتصميم المشاريع ال

:الخالصة و التوصيات . هـ

:وتشمل ما يلي خالصة الدراسة •

.اقتراح خيارات التصميم .التوصيات بحلول المشاكل .التوصيات بدراسات مستقبلية الحقة

:المالحق . و

جيـة، خـرائط تصـنيف والخرائط الجيومورفول(وتشتمل على الخرائط الجيولوجية الهندسية الحسابات التحليلية لثبات الميول وتقدير معامل األمان، ) الخ...ميول الصخور، خرائط ثبات ال

.سجالت الحفر ونتائج الدراسة الحقلية والمعملية، الصور الفوتوغرافية للمنطقة

:املراجع . ٤

1. Rock and Soil Description and Classification for Engineering Geological

Mapping, Bulletin of International Association of Engineering Geology,

No. 24, pp. 235-274, 1981.

2. Basic Geotechnical Description of Rock Masses, Int. Rock Mech. & Min.

Sci. & Geomech. Abst. Vol. 18, pp. 85-110, Pergamon Press Ltd., 1981.


٦٣

3. ENGINEERING GEOLOGICAL REPORT:

Engineering Geological reports should include, but not illustrate to, the following

sections:

(b) Introduction:

• Description of the project

• Purpose of the study

• Geological, topographical, and land use maps.

(c) Geology: and Geomorphology

• Description of the rock type and the structure of the rock masses.

• Types of the deposits on the surface and their thickness

• Geological maps.

• Description of outcrops: rock type, weathering, joints and their characteristics.

•

(c) Scope of study: (Engineering geological Description)

• Description of rocks and their characteristics such as: type, mineral

composition, strength, etc. Description of the field and laboratory tests that have

been conducted to get these characteristics.

• Description of rock masses and their characteristics such as:

- Dip and strike - Layer thickness - Fracture intercept - Uniaxial compressive strength - Angle of internal friction - Joint spacing - Joint roughness - Aperture - Infilling materials. - Rock Quality Designation (RQD) - Location of groundwater table.


٦٤

(d) Results and analysis:

Test results must be given in detail. The results should be discussed and analyzed

to get the required engineering parameters to determine the stability of slopes

and excavations of the underground projects such as tunnels and other

geological projects. The parameters should be put with their final values on

engineering geological maps, which enable engineers to design the engineering

projects, and engineering geological maps.

(e) Summary and Recommendations:

• Summary of the project.

• Design alternatives.

• Recommendation of the problem solution.

• Recommendation for future studies

• Determination of the best method for construction.

(f) Appendices:

Include the engineering geological maps (such as geomorphological maps, rocks

classification maps, slope stability maps, ….etc.), calculation of the slope

stability analysis and factor of safety, borehole logs, results of the field and

laboratory tests, photography of project area, etc.

4. REFERENCES:

1. Rock and Soil Description and Classification for Engineering Geological

Mapping, Bulletin of International Association of Engineering Geology, No. 24,

pp. 235-274, 1981.

2.Basic Geotechnical Description of Rock Masses, Int. Rock Mech. & Min. Sci. &

Geomech. Abst. Vol. 18, pp. 85-110, Pergamon Press Ltd., 1981.

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