第六章--土压力-土力学课件.ppt
岩土工程研究所第六章第六章 土压力土压力Research Institute of Geotechnical Engineering,Hohai UniversityChapter 6 Earth Pressure岩土工程研究所第一节第一节 概述概述 IntroductionIntroductionn n土压力概念土压力概念土压力概念土压力概念 What is earth pressure?What is earth pressure?n n土压力种类：土压力种类：土压力种类：土压力种类：Types of earth pressureTypes of earth pressuren n静止土压力：静止土压力：静止土压力：静止土压力：Earth pressure at restEarth pressure at rest岩土工程研究所n nWhat is earth pressure?What is earth pressure?第一节第一节 概述概述 IntroductionIntroductionEarth pressure:Earth pressure:The pressure applied on The pressure applied on a retaining wall from soil a retaining wall from soil 岩土工程研究所第一节第一节 概述概述 IntroductionIntroduction主动土压力主动土压力主动土压力主动土压力 Active earth pressureActive earth pressure被动土压力被动土压力被动土压力被动土压力 Passive earth pressurePassive earth pressure静止土压力静止土压力静止土压力静止土压力 Earth pressure at restEarth pressure at restn nTypes of earth pressure?Types of earth pressure?岩土工程研究所岩土工程研究所第一节第一节 概述概述 IntroductionIntroductionUnder natural conditions of deposition,with semi-infinite extent,there is a negligible amount of horizontal strain,the soil is said to be in an at-rest state(or K0 state),and the horizontal effective stress is:Where K0=coefficient of earth pressure at rest.n nAt-rest earth pressure?At-rest earth pressure?The resultant thrust is equal to the area of the pressure distribution diagram,I.e.岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theory Rankines theory n nActive earth pressure Active earth pressure in cohesionless soilsin cohesionless soils Smooth vertical back,Smooth vertical back,horizontal surfacehorizontal surface The wall moves away from the earthfill,The wall moves away from the earthfill,Vertical stress is major principal stress Vertical stress is major principal stress Soil in state of Soil in state of plastic equilibriumplastic equilibriumKa is coefficient of active earth pressureKa is coefficient of active earth pressure岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nActive earth pressure Active earth pressure in cohesionless soilsin cohesionless soils Pressure distributionA uniform A uniform surcharge load surcharge load(q)is applied(q)is applied over the whole over the whole surfacesurface The wall moves away from the earthfill,The wall moves away from the earthfill,Vertical stress is major principal stress Vertical stress is major principal stress 岩土工程研究所岩土工程研究所 The wall moves towards the earthfill,The wall moves towards the earthfill,Vertical stress is minor principal stress Vertical stress is minor principal stress第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nPassive earth pressure Passive earth pressure in cohesionless soilsin cohesionless soils H/3K Kp p is coefficient of is coefficient of passive earth passive earth pressurepressurePassive earth pressure岩土工程研究所 Vertical stress is minor principal stressVertical stress is minor principal stress第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nPassive earth pressure Passive earth pressure in cohesionless soilsin cohesionless soils K Kp p is is coefficient of coefficient of passive earth passive earth pressurepressureThe resultant thrust is equal to the area of the pressure distribution diagram The line of action of Pp passes through the center of the area of the pressure distribution diagram 岩土工程研究所岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nActive earth pressure Active earth pressure in cohesive soilsin cohesive soils Assuming:Tension crack depth:(c)(d)If Z00,then case(c);岩土工程研究所岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nPassive earth pressure Passive earth pressure in cohesive soilsin cohesive soils 岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nPassive earth pressure Passive earth pressure in cohesive soilsin cohesive soils 岩土工程研究所岩土工程研究所第二节第二节 朗肯土压力理论朗肯土压力理论Rankines theoryRankines theoryn nActive earth pressure Active earth pressure in stratified soilin stratified soil12Layer 1Layer 2岩土工程研究所 谢谢谢谢！Thank You!-结束 The END-岩土工程研究所总结总结 SummarySummaryn nToday,in the following hours I am going to introduce Today,in the following hours I am going to introduce chapter 6 using English.My spoken English is not so chapter 6 using English.My spoken English is not so good.This is the first time that I have had a class in good.This is the first time that I have had a class in English.It is really a challenging task for both you and English.It is really a challenging task for both you and me.I am not sure whether I can success,but I will do me.I am not sure whether I can success,but I will do my best to make you understand what I mean.I hope my best to make you understand what I mean.I hope all of you support me.all of you support me.
