高等土力学复习题

硕士研究生《高等土力学》复习思考题

一(a)、将下面描述“土力学和岩土工程”的英文译成中文

Soil Mechanics

This class presents the application of principles of soil mechanics. It considers the following topics: the origin and nature of soils; soil classification; the effective stress principle; hydraulic conductivity and seepage; stress-strain-strength behavior of cohesionless and cohesive soils and application to lateral earth stresses; bearing capacity and slope stability; consolidation theory and settlement analyses; and laboratory and field methods for evaluation of soil properties in design practice.

Soil amongst most variable and difficult of all materials to understand and model 1. Complex stress-strain (non-linear, irreversible不可逆的)

2. Properties highly variable function of soil types and stress history

3. Properties change with time, stress, environment, …

4. Every site has different soil conditions - new challenge

5. Soil "hidden" underground and data on small fraction of deposit

Geotechnical Engineering This course describes the application of soil mechanics in the analysis and design of foundations (shallow and deep) and earth retaining structures. The lectures include an overview of geotechnical site investigation methods and in situ tests used to estimate engineering parameters. The course emphasizes the importance of parameter selection in calculations of ultimate and serviceability limit state calculations for both shallow and deep foundations, and discusses methods of soil improvement. The section on earth retaining structures considers systems ranging from gravity walls to composite construction (reinforced earth), from structural support to field monitoring of excavations (bracing, tieback anchors etc.).

(1)What is consolidation?

Consolidation is a time-related (时间性) process of increasing the density (增加密度) of a saturated soil by draining some of the water out of the voids.

(2)The shear strength of a soil [土的抗剪强度] ( f) at a point on a particular plane was originally expressed by Coulomb as a linear function of the normal stress ( ’f) on the plane at the same point by

f c' 'f tan '

where c’ is cohesion [粘聚力] and ’ is internal angle of friction [内摩擦角].

(3) Ultimate bearing capacity (qu) is defined as the pressure which would cause shear failure of the supporting soil immediately below and adjacent to a foundation. (当基底压力增大到极限承载力时,地基出现剪切破坏)

(4) Allowable bearing capacity (qa) is defined as the maximum pressure which may be applied to the soil such that the above two requirements are satisfied. From first requirement, qa is defined as: (地基的容许承载力 qa 定义为当上述两个条件满足时的基底最大压力.当条件一满足时qa 定义如下)

qa quFs

(5) A foundation must satisfy two fundamental requirements: (设计基础要满足两个要求 ) (a) the factor of safety Fs against shear failure of the supporting soil must be adequate, a value between 2 and 3 normally being specified (地基达到剪切破坏的安全糸数 Fs 要适当,一般在2至3之间 )

(b)the settlement of the foundation should be tolerable and, in particular, differential settlement should not cause any unacceptable damage of the structure (基础的沉降和沉降差必须在该建筑物所允许的范围之内)

一(b)、《高等土力学》研究的主要内容。

二、与上部结构工程相比，岩土工程的研究和计算分析有什么特点？

三、归纳和分析土的特性。

四、简述土的结构性与成因，比较原状土与重塑土结构性强弱，并说明原因？

五、叙述土工试验的目的和意义。

七、岩土工程模型试验要尽可能遵守的原则？

八、何谓土的剪胀特性？产生剪胀的原因？

九、影响饱和无粘性土液化的主要因素有哪些？举出4种判断液化的方法。

十三、土的本构模型主要可分为哪几类？邓肯-张本构模型的本质？并写出邓肯-张本构模型

应力应变表达式，并在应力应变座标轴中表示。

十四、广义地讲，什么是土的本构关系？与其他金属材料比，它有什么变形特征？ 十五、在土的弹塑性本构关系中，屈服准则、硬化定理、流动法则起什么作用？

十六、剑桥模型的试验基础及基本假定是什么？说明该模型各参数的意义及确定方法。

十九、试说明屈服点、屈服准则、屈服面、塑性变形和破坏的概念？示意理想弹塑性材料、

弹性塑性应变硬化材料、弹性塑性应变软化材料的应力应变关系？并示意土的典型应力-应变关系曲线（并加以描述）？

二十、影响饱和土渗透性的主要因素？

二十一、何谓前期固结压力？简述前期固结压力的确定方法。

二十二、何谓Mandol-cryer效应？说明其产生机理。

二十三、分析影响地基沉降的主要原因、机理和性质。

二十四、何为应力路径？采用应力路径法计算沉降时常采用哪两种方法？简述其各自的计算

步骤。

二十六、地基压缩层厚4m，通过钻探采取代表性原状土样，测得其初始孔隙比e0＝1.0，有

效内摩擦角 ′＝25°, c′=15kPa，土的压缩指数cc＝0.31。试样在20、40、60kPa等围压下固结，然后作三轴CU试验，分别测得其有效应力路径如图1所示。设K0=1－sin ′，如果土层中点原上覆土压力为64kPa，由于修建建筑物，附加应力为Δ ＝28.5kPa，Δ ＝10.5kPa，用应力路径法计算瞬时加荷后地基的瞬时沉降和固结后总沉降。

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