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Dr hammida

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Seismic Earth Pressures on Retaining Structures and

Basement Walls

ABSTRACT

Observations of the performance of basement walls and retaining

structures in recent earthquakes show that

failures of basement or deep excavation walls in earthquakes are

rare even if the structures were not designed for the

actual magnitude of the earthquake loading. For instance, no

significant damage or failures of retaining structures

occurred in the recent Wenchuan earthquake in China (2008)

and the subduction earthquakes in Chile (2010) and

Japan (2011). To develop a better understanding of the

distribution and magnitude of the seismic earth pressures on

cantilever retaining structures, a series of centrifuge experiments

were performed on model retaining and basement

structures with cohesionless and cohesive backfills.

Seismic soil pressures

In the present state of knowledge, the recommended method of

obtaining seismic soil forces is that using equivalent-static

analysis. Only for exceptional structures would dynamic analyses

using finite elements seem warranted.

In the equivalent-static method, a horizontal earthquake force

equal to the weight of the soil wedge multiplied by a seismic

coefficient is assumed to act at the centre of gravity of the soil

mass. This earthquake force is additional to the static forces on the

wall.

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In general, the total soil pressure on a wall during an earthquake

equals the sum of three possible components:

(1) static pressure due to gravity loads;

(2) dynamic pressure due to the earthquake;

(3) pressure due to the wall being displaced into the backfill by an

external force, e.g. by the horizontal sway of a bridge deck at a

monolithic abutment

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Aleppo University - Faculty of Civil Engineering

A scientific conference in the terms of reference of Civil

Engineering

Resisting the walls of basements and retaining pressure

from the soil of earthquakes

Introduction:

In this research is to clarify how seismic pressures

on retaining walls calculation

And designed to show how the earthquake

resistance in accordance with the requirements of

the Arab code Syrian - Supplement No. 2

As it is explained how to account solving practical

example for the design of retaining wall of

resistance Earthquake for multiple cases of the

existence of water or non-existent.

Seismic Pressure on Basement & retaining walls:

2-1 calculation Pressure from the soil without

earthquakes:

The state of the soil is homogeneous method is

adopted to calculate the Coulomb soil pressure

Retaining walls on the side where it is supposed

that the surface of plane collapse

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Syrian Code

the design loads earthquakes extension

retaining Walls and soil pressure من الكود السوري ملحق تصميم الزالزل

Seismic Earth Pressures on Retaining Structures

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Example- 1

calculation Soil pressure from earthquakes

to the wall and the foundation According to Figure 5

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Example- 2

calculation Soil pressure from earthquakes

to the wall and the foundation According to Figure 5

Example- 3

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calculation Soil pressure from earthquakes

to the wall and the foundation According to Figure 5

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Example- 4

calculation Soil pressure from earthquakes

to the wall and the foundation According to Figure 5

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The water pressure on the walls

In the case of earthquakes

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Example No. 5

The water pressure on the walls

in the restricted case

In earthquakes

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2012 طبعة

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Dr Hammida