电大岩土力学试题2答案小抄

1、一、填空题（本大题共5小题，每小题3分，总计15分）1、土的三相组成是指： 固相 、 液相 、 气相 。2、土层中的毛细水带分：正常毛细水带、毛细网状水带、毛细悬挂水带三种。3、土的三轴试验方法分：不固结不排水剪、固结不排水剪、固结排水剪。 4、均质粘性土圆弧滑动面的形式有：坡脚圆、坡面圆、中点圆。5、地基剪切破坏的形式有：整体剪切破坏、局部剪切破坏、刺入剪切破坏二、选择题（在每个小题四个备选答案中选出一个正确答案，填在下面表格中） （本大题共5小题，每小题3分，总计15分）题号12345答案dcdba1、已知土的重度，土颗粒重度s、土的含水量、水的容重w，则浮重度为（a） （b） （c） -

2、 （d） 2、已知某粘性土的液限为42%，塑限为22%，含水量为52%，则其液性指数、塑性指数分别为：（a） 20、1.5 （b） 20、30（c） 1.5、20 （d） 1.5、303、某土层厚度为3m，重度为19，则该土层深2m处的自重应力为：（a） 5.7 kpa （b） 3.8 kpa（c） 57 kpa （d） 38 kpa4、已知土层的前期固结压力为0.2mpa，土层自重应力（即自重作用下固结稳定的有效竖向应力）为0.3 mpa，则该土层属于：（a） 超固结土 （b） 欠固结土（c） 正常固结土 （d） 不能确定5已知某土样内摩擦角，粘聚力为，承受最大主应力和最小主应力分别为，则该

3、土体：（a） 处于极限平衡状态（b） 未达到极限平衡状态，土体没有破坏（c） 已超过极限平衡状态，土体已经破坏（d） 条件不足，无法判断三、 计算题(共2小题，总分30分)1、某重力式挡土墙墙高h10m，墙背直立光滑，墙后填土面水平。填土分为两层，上层土体位于地下水位以上，下层土体位于地下水位以下。填土的主要物理力学指标如图所示 , 填土面作用均布荷载试求该挡土墙上的主动土压力分布、合力大小。（15分） 解：主动土压力系数：（2分）； a点：（2分） b点上：（2分） b点下：（2分） c点：（2分）因为，所以，故认为土层不受到浮力的作用 其分布如下图所示：（1分）开裂高度：ac=（2分）所以

4、合力为：（2分）2、有一矩形面积（ab=5m，ad=3m）三角形分布的荷载作用在地基表面，荷载最大值p=100kp（a），计算矩形面积内o点（ae=1m，ah=1m）下深度z=3m处的竖向应力的大小。（15分）矩形面积上作用均布荷载时，角点下竖向应力系数值深宽比矩形面积长宽比234500.2500.2500.2500.2500.250待添加的隐藏文字内容20.2500.2500.2500.20.2490.2490.2490.2490.2490.2490.2490.2490.40.2400.2420.2430.2430.2440.2440.2440.2441.50.1200.

5、1300.1410.1430.1560.1600.1630.16830.0450.0520.0580.0640.0730.0870.0930.096矩形面积上作用三角形分布荷载时，压力为零角点下竖向应力系数值1.02.03.04.08.00.00.0000.0000.0000.0000.0000.0000.0000.0001.00.02010.05010.05080.05660.07700.07900.07920.07961.50.01300.0320.03600.05200.0690.07000.07010.07322.00.00900.02510.0255.0.03840

6、.05900.06070.06200.06363.00.00460.01300.01350.0210.04000.04190.0450.0474解：（1）荷载作用面积叠加计算：（7分）应力系数查表得：=0.045（矩形aeoh）；=0.093（矩形ebfo）；=0.156（矩形ofcg）；=0.073（矩形hogd）（2）荷载分布图形叠加计算：（8分）应力系数查表得：=0.021（矩形aeoh）；=0.045（矩形ebfo）；=0.069（矩形ofcg）；=0.032（矩形hogd）四、 问答题(共5小题，总分40分)1. 什么叫粘性土的塑限、液限、塑性指数和液性指数？怎样测定？（10分）答：

7、（1）塑限：粘性土由半固态变到可塑状态的分界含水量，称为塑限。用“搓条法”测定；（3分） （2）液限：粘性土由可塑状态变化到流动状态的分界含水量，称为液限。用“锥式液限仪”测定；（3分） （3）塑性指数：液限与塑性之差。（1分） （4）液限指数：，天然含水量用“烘干法”测定。（3分）2、什么叫动水力？试写出其数学表达式，并分析流砂产生的原因及条件？（8分）答：（1）地下水在渗流过程中，对单位体积土骨架所产生的作用力，称为动水力；（2分） （2）动水力的数学表达式为：（2分） （3）原因及条件：地下水向上渗流，且（4分）3、什么叫土的抗剪强度？其测定方法有哪些？（8分）答：（1）土体抵抗剪切破坏

8、的极限承载能力，称为土的抗剪强度（3分） （2）测定方法有：直接剪切试验；三轴剪切试验；无侧限抗压试验；十字板剪切试验；大型直接剪切试验。（5分）4、什么是地基承载力？有哪几种确定方法？（6分）答：（1）是指地基土单位面积上所能承受荷载的能力；（3分） （2）确定方法有：现场载荷试验；理论计算；规范法。（3分）5、分析冻胀产生的原因，及冻胀现象对工程的危害？（8分）答：（1）其主要原因是，冻结时土中未冻结区水分向冻结区迁移和积聚的结果；（3分） （2）对工程危害：使道路路基隆起、鼓包，路面开裂、折断等；使建筑物或桥梁抬起、开裂、倾斜或倒塌。（5分）winger tuivasa-sheck, w

9、ho 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 not

10、 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 the

11、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 award

12、 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 at c

13、helsea 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 their

14、 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 from f

15、ans 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 limited c

16、loud 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 airl

17、iners (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 olymp

18、ic 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 josh

19、 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 of