Introduction to Earth Retaining Structures

Indra S. Harahap – Foundation and Earth Retaining Structure - Jul07/Jan08

Earth Retaining Structure


Objectives

• To outline the engineering aspect of earth retaining structures, based on their basic principles, method of analysis and design and potential problem to the environment


Lecture Outcomes:

1. Able to explained different type of earth retaining structure particularly construction method, material used, and its salient characteristics,

2. Able to relate method of construction of earth retaining structures to their response under external loading,

3. Able to select a suitable type of earth retaining structure, from a list of possible selections, based on (a) soil type and its layering system and (b) environment constraints,

4. Able to design earth retaining structure based on (a) stability and (b) structural integrity criteria.


Example of Earth Retaining Structures


• Rigid retaining wall & Sheetpile wall

Keywords: retaining wall, sheet pile wall


• Crib Wall

Keywords: stretcher, header, cells, soil


• Gravity Wall and Cantilever Wall

Keywords: height


• Conterfort wall

Keywords: gravity wall, cantilever wall, counterfort wall


• Soil reinforcement


• Reinforced Earth Wall


• Fabric Reinforced wall


• Braced Excavation

Keywords: settlement, strut, wale beam


• Soil Nailing


Topics on Earth Retaining Structure

– Lateral Earth Pressure– Rigid and Semi Rigid Wall

• Crib wall

• Gravity wall and Cantilever wall

– Flexible Wall• Cantilever Sheetpile

• Anchored Sheetpile

– Mechanically Stabilized Earth– Braced Excavation


Analysis and Design of Earth Retaining Structure

1. Determination of load acting on earth retaining structure

2. Check strength and stiffness of structural components

3. Check structural stability (horizontal displacement, overturning, bearing capacity, general stability)


• Failure modes of gravity structure

Keywords: mechanisms, bearing capacity, overturning, sliding, general failure, centre of rotation


• General stability

Keywords: shear key, alternative location


• Failure mode of reinforced earth wall

Keywords: metal strip, spacing, star-shaped element, stress distribution, actual failure surface


• Bearing capacity failure of reinforced earth wall

Keywords: base failure


• Failure mode of cantilever and anchored sheetpile wall

Keywords: plastic hinge, rotation


• Problem statement of braced excavation

Keywords: settlement, strut, wale beam


Summary of Previous Lecture

• Discuss various types of earth retaining structure• Discuss failure mechanism of earth retaining

structure• Discuss of procedure of design of earth retaining

structure


Analysis and Design of Earth Retaining Structure

1. Determination of load acting on earth retaining structure

3. Check strength and stiffness of structural components

2. Check structural stability (horizontal displacement, overturning, bearing capacity, general stability) based on failure mechanisms


Any question?

Documents

Introduction to Earth Retaining Structures