PRESENTATIONON

MAT FOUNDATION

Department of Civil Engineering

1

Md. Abdul Ahad12-01-03-104

Presented By

Monisha Podder12-01-03-110

Arafat Chowdhury12-01-03-116

Sabrina Zissan12-01-03-124

Mahbub Al Muhaimin12-01-03-129

Abu bakar Siddik12-01-03-136

Sabrina Mehenaz12-01-03-144

Visited Sites

Arham Tower, Uttara

Pallabi, Mirpur-11

Euro Bangla Real Estate,

Mouchak

MAT Foundation• Primary shallow foundation;

• Also known as Raft;

• Large footing extended over the whole construction area;

• Supports many columns;

• Foundation for high rise buildings with basement;

• Depth 1~20 feet.

PCC BED

R C C SLAB

C C

Sectional View

Plan View

COLUMN

MAIN BEAM

SECONDARY

BEAM

MAIN BEAM

When we construct MaT foundation?

• When the area of individual column footings cover

more then 50% area of total land;

• When the bearing capacity of soil is too weak to

support a structure;

• When the cost of deep foundation is higher then

Raft foundation.

• When the structural load is too high.

Types of MAT

Flat Plate MatTwo-way Beam & SlabFlat Plate Thickened Under

Column

Flat Plate with Pedestals Pile Mat Rigid Frame mat

construction Procedures

Soil test

Shoring & Water

proofing

Partial Excavation

(depending on depth)

Bracing (depending on

depth)

Full area excavation

Soil compaction

BFS & CC or LC layer cover

Reinforcement placing

Shuttering

Casting & Compaction

Shuttering removal

Curing

Soil Test

• Bearing capacity of

soil;

• Soil classification;

• Ground water level;

• Moisture content;

• Appropriation & depth

of MAT.

Shoring• Shoring is commonly used when installing the

foundation;

• Shoring support the surrounding loads until the

underground levels of the building are

constructed.

• Can be of 3 types: Pile shore, steel sheet shore

and timber shore.

Log Shore Pile Shore

Steel Shoring

Water proofing

• A layer provided over

shoring to prevent

moisture;

• Cement mortar or steel

sheet layer over

shoring;

• Cement mortar layer is

extended over wire

mesh.

Bracing

• A horizontal support for

the boundary shores

during excavation and

foundation;

• Depends on the depth of

foundation;

• Also known as horizontal

shores.

Other factors

Shotcrete leveling

layer with steel mesh

Retaining Wall

King Post

BFS and CC

Layer of bricks

on the earth

Layer of cement

concrete over BFS.

Reinforcement placing

• A batch of horizontal reinforcement placing;

• Another batch of reinforcement placement to complete the bottom mesh;

• Column rod placement;

• Vertical rod (chair) placement over bottom mesh to hold the upper mesh;

• Upper mesh placement.

Important factors

Reinforcement Selection

• 60~72.5 Graded

• 12mm~25mm

Reinforcement Joint

• Heavy Steel wire binding

Chair

• Distance

• Bending

Important factors

Hook

• Right angled

Rod Cutter

Rod bender

Shuttering

• Steel plate shutter;

• Timber shutter.

Cast Material

• Mixture ratio 1:2:4;

• Sylhet sand is used

over 50%;

• Stone chips that are

used normally is

½”~¾” in size;

• Stone chips are

preferred than brick

chips.

Casting

• Start from one end;

• Layer basis casting;

• Side basis casting.

Compaction

• By vibrator machine;

• Compaction and

casting both are done

simultaneously;

Precautions for casting

• Materials like piece of wood, polythene etc. must be

removed before casting from that area;

• Shuttering must be leak proof;

• Cast pouring height is less than 5 feet ;

• Pouring and compaction both are done simultaneously.

Curing