电大岩土力学试题4答案小抄

1、一、填空题（22分，每空2分）1、工程上常用不同粒径颗粒的相对含量来描述土的颗粒组成情况，这种指标称为粒度成分。2、计算地下水位以下土层的自重应力时应当用有效重度。3、粘性土可塑性大小可用塑性指数来衡量。用液性指数来描述土体的状态。4、达西定律指出，水在砂性土体中渗流过程中，渗流速度与水头梯度成正比。5、动水力指水流作用在单位体积土体中土颗粒上的力。6、土力学中的有效应力原理包含下述两点：土的有效应力等于总应力减去孔隙水压力；土的有效应力控制了土的变形及强度性能。7、土坡滑动失稳的原因有：外界力的作用破坏了土体内原有的应力平衡状态；土的抗剪强度由于受到外界各种因素的影响而降低。二、选择题（30

2、分，每题3分）1、已知土的、，则孔隙比为（ b ）（a）0.66 （b）0.76 （c）0.86 （d）0.962、下述试验方法中，属于粒度成分分析的试验是（ a ）（a）沉降分析法 （b） 标准贯入试验（c）搓条法 （d）原位压缩试验3、前期固结压力是指（ d ）（a）土体在形成过程中所受到的最大总应力（b）土体在固结过程中所受到的最大总应力（c）土体在形成过程中所受到的最大有效应力（d）土体在固结过程中所受到的最大有效应力4、饱和粘性土地基沉降的三个阶段不包括（ c ）（a）瞬时沉降阶段 （b） 次固结沉降阶段（c）超固结沉降阶段 （d）固结沉降阶段5、在剪切试验中，若采用对试样施加竖向压

3、力后让试样充分排水，待固结稳定后，再快速施加水平剪应力使试样破坏。这种试验方法属于（ b ）（a）快剪 （b） 固结快剪（c）慢剪 （d）固结慢剪6、关于压缩模量叙述正确的是（ a ）（a）压缩模量用于分层总和法、应力面积法的地基最终沉降计算中（b）压缩模量用于弹性理论法的地基最终沉降估算中（c）压缩模量用于估算建筑物的初始瞬时沉降（d）压缩模量是根据现场载荷试验得到的7、土层的平均固结度等于（ c ）（a）总应力图面积/有效应力图面积（b）总应力图面积/起始超孔隙水压力图面积（c）有效应力图面积/起始超孔隙水压力图面积（d）起始超孔隙水压力图面积/总应力图面积8、已知土的内摩擦角为，滑动面上

4、的法向应力为100kpa，土的粘聚力100kpa，则由库仑定律可求得抗剪强度（ b ）（a）100kpa （b） 200kpa（c）300kpa （d）400kpa9、粘性土的等效摩擦角是（ d ）（a）根据有效应力原理来计算的（b） 将滑动面上的法向应力折算为内摩擦角（c）根据静力平衡原理来计算的（d）根据抗剪强度相等原理来计算的10、在粘性土的土坡稳定分析中，对于非均质土坡或较复杂土坡的适用方法是（ c ）（a）摩擦圆法 （b） 泰勒分析法（c）条分法 （d）分层总和法三、证明题（10分）1、若已知各层土的渗透系数为，厚度为（其中），试证土层竖向平均渗透系数的表达式为：证： （2分） （2

5、分）（2分） （4分）四、计算题（70）1、某饱和土的体积为97 土的重力为1.98n，土烘干后重力为1.64n，试计算烘干前土体的含水量、孔隙比、干重度。(15分)解：水的重力为1.981.64=0.34n（2分）水的体积为=0.34/9.81=34.7（2分）土粒体积为=9734.7=62.3（2分）含水量：（3分）孔隙比（3分）干重度（3分）2、按图所给资料计算并绘制地基中的自重应力沿深度的分布曲线，各层重度如下：（20分）解：在41.0高程处：（4分）在40.0高程处：（4分）在38.0高程处：（4分）在35.0高程处：（4分）画图（4分）3、某挡土墙的墙壁光滑（），墙高7.0m（如图

6、），墙后1、2两层填土。1层土位于地下水位以上，性质为：土层厚度3.5m，。2层土位于地下水位以下，性质为：土层厚度3.5m，。填土表面作用有连续均布荷载，试求作用在墙上的总主动土压力、水压力及其作用点位置。（35分）解：主动土压力系数：（6分），沿墙高计算a、b、c三点的土压力强度：（12分）a点：z=0，b点：分界面以上，分界面以下，c点：作用在墙上的总主动土压力：（4分）水压力：（4分）作用于距墙底3.5/3=1.17m处（3分）的作用点位置：（6分）的作用点距墙底高度为：h=3.08m五、问答题（共28分）1、固结度与哪些因素有关？（8分）答：（1）渗透系数（2分）（2）值（2分）（3

7、）时间（2分）（4）渗流路径（2分）2、均质粘性土的土坡失稳破坏时，圆弧滑动面的形式有哪几种？（6分）答：（1）坡角圆（2分）（2）坡面圆（2分）（3）中点圆（2分）3、地基破坏的过程经历哪几个阶段，各自的特点是什么？（8分）答：压密阶段，曲线接近直线，土体处于弹性平衡状态（3分）剪切阶段，曲线不再是直线，土体出现塑性区（3分）破坏阶段，出现连续滑动面，土坡失稳破坏（2分）4、在计算最终沉降量时，应力面积法与分层总和法相比，有哪些特点？（6分）答：（1）计算结果更精确，计算工作量更少（2分）（2）计算方法更合理（2分）（3）提出了终沉计算经验系数（2分）winger tuivasa-sheck

8、, who scored two tries in the kiwis 20-18 semi-final win over england, has been passed fit after a lower-leg injury, while slater has been named at full-back but is still recovering from a knee injury aggravated against usa.both sides boast 100% records heading into the encounter but australia have

9、not conceded a try since josh charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer with nine, closely followed by tuivasa-sheck with eight.but it is recently named rugby league international federation player of t

10、he year sonny bill williams who has attracted the most interest in the tournament so far.the kiwi - with a tournament high 17 offloads - has the chance of becoming the first player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every aw

11、ard back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys premier league match a

12、t chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of th

13、eir fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults fro

14、m fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limite

15、d cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial a

16、irliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will slowly drift to the edge of space at 120,000 feet ( then, i would assume, he will slowly step out onto something resembling an ol

17、ympic diving platform.they blew it in 2008 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands j

18、osh charnley in the opening game of the tournament.that could be classed as a weakness, a team under-cooked - but i have been impressed by the kangaroos focus in their games since then.they have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completing sets and a good kick-chase. theyve been great at all the unglamorous stuff that often goes unnoticed in the sta