Abdul Razzaq Touqan طوقان الرزاق عبد

Soil-Structure Interactionالبناء مع األساس تفاعل

مقدمة عالقة في التغيير رساالت من رسالة أوضح الزالزل

: إما تبين فهي باألساس البناءالمخرجات سلمت إذا والمعالجة المدخالت صالحية

أو

المدخالت أو المعالجة أو المدخالت في خللخلل األساس أو البناء أصاب إذا والمعالجة

انهيار أو نفعي

Input processing output

Introduction

INPUT: Representation of mathematical model

INPUT: Representation of earthquake loadings

PROCESSING: Representation of mass and stiffness properties: analogical models

PROCESSING: Representation of mass and stiffness properties: anatomical models

OUTPUT: Models comparisons

OUTPUT: Conclusions

Further usage of concept

Reminder

Fundamental lesson learned from earthquakes: Necessity of correct matching between mathematical model

and reality (input)

Necessity of correct matching between earthquake loadings and method of analysis (processing)

Introduction

Representation of Mathematical Model

-Soil theory is based on assumption of rigid structures built on flexible foundations.

-Structural theory is based on assumption of flexible structures built on rigid foundations.

Methods of analysis:

1. Time history: true dynamic analysis, all necessary modes of soil-structure model

2. Response spectrum: one point dynamic analysis, all necessary modes of soil-structure model

3. Equivalent lateral load: static analysis, one mode of structure model

Representation of Earthquake loadings:

basic assumptions of equivalent lateral load General assumptions: uniform distribution of

mass and stiffness. Special assumptions: models used based on

level of technology

maxV Ma

Representation of Earthquake loadings: Equivalent lateral load

a one-story flat plate reinforced concrete building subjected to earthquake loading in the x-direction..

ASCE/SEI 2010 0.90.0466 0.13secnT h

the relative displacement output u* of a 1D model subjected to an earthquake

M, K and ß are mass, stiffness and acceleration response spectrum (dynamic magnification factor) respectively

*max

Mu

K

Representation of mass and stiffness properties: analogical models

For simplicity assume 1D model composed of two springs in series. The combined stiffness K

If Ksoil is much larger than Kstr then the combined stiffness K is equal to Kstr and separation between soil and structure is justified

1 /soil str str

soil str str soil

K K KK

K K K K

Representation of mass and stiffness properties: analogical models

Substructuring concept: static reduction

Representation of mass and stiffness properties: analogical models:

Substructuring concept: static reduction

Representation of mass and stiffness properties: analogical models

Substructuring concept: dynamic reduction

Representation of mass and stiffness properties: analogical models

Representation of mass and stiffness properties: anatomical models

Models comparisons

-Neglecting soil structure interaction is reasonable if assumptions prevails like:

- light structures in relatively stiff soil such as low rise buildings, structural assumptions prevails.

- simple rigid retaining walls: foundation assumptions prevails.- -The effect of soil structure interaction becomes important for

heavy structures resting on relatively soft soils for example towers in a wadi (like wadi altufah)

ان5 7م5يز6 ال ف5ي 6ط7غ6و7ا ت ال96 أ

Conclusions

Further usage of concept

Models comparisons

1. Best structural shape to resist lateral loadings (wind, earthquake, …) is the pyramid shape. Such shape provides largest stiffness and smallest mass

2. Worst structural shape to resist lateral loadings is the inverted pyramid shape. Such shape provides largest mass and smallest stiffness

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By the same philosophy, weakness in the soil increases mass and decreases stiffness, thus structure becomes vulnerable to earthquake loads.

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6 أ 7ر: ي خ6 Cو6ر5ض7و6ان 9ه5 الل م5ن6 6ق7و6ى ت ع6ل6ى 6ه> 6ان 7ي >ن ب س9س66 أ ف6م6ن7

6 أ) 5م5ين6 الظ9ال 7ق6و7م6 ال 6ه7د5ي ي ال6 9ه> و6الل 9م6 ج6ه6ن 6ار5 ن ف5ي 5ه5 ب 7ه6ار6 ف6ان Cالتوبة)109ه6ار

Conclusions for further usage

Reminder تذكيرالبناء مع األساس تفاعل

/ أساس/ بنيان بناء

م* ب,ن*ي-ان-ه, الل/ه, أ-ت-ى ف- م* ب*ل2ه2 ق- م2ن* ال/ذ2ين- ك-ر- م- د* ن- ق- م2د2 و-اع2 م* ال*ق- ه2 و*ق2 ف- م2ن* ف, ق* الس/ م, ع-ل-ي*ه2 ر/ خ- ف-

( ون- ع,ر, ي-ش* ال- ي*ث, ح- م2ن* ال*ع-ذ-اب, م, -ت-اه, أ 1927(26و-النحل

Thank you for listening

What is your opinion of a structure with basement wall on one side as a usual practice in Palestine?

Question