地下洞室开挖过程中洞周损伤分布的时变反演

洞室开挖过程中，洞周围岩的损伤场是时间和空间的函数。本文由建立的岩体时变损伤本构模型，基于位移反演理论，依据各步开挖后洞周及深部测线量测位移，对地下洞室由开挖引起的时变损伤分布情况进行辨识。通过构造损伤分布拟合函数直接反演洞周损伤分布的时变过程，尝试了用拟合函数法实现动态分布参数的反分析。在对某直墙半园拱顶隧道进行反演时，将洞室边界映射成单位圆，建立了由衰减函数和傅立叶级数构成的拟合函数，并采用约束优化法反演。最终结果显示，反演得到的区域损伤平均值与真值相比，绝大多数误差较小。本文法在地下工程施工的岩体内部损伤监测中具有一定的参考价值。     

解析与数值结合法及其应用

评述了解析与数值结合法发展的基础、研究的内容、分类、特点及应用和发展前景。     

An analytical solution for underground structure-country rock dynamic interaction

In this paper according to the results of a great quantity of tests and numerical calculations, it is pointed out that the surrounding rock with thickness of 1/3 span has mechanical characteristics of a thick flexural member in underground rock cave subjected to transverse blast loading. However, it approaches the stress state of free field outside country rock and the equation of thick plate theory under the loading of free field pressure may be applied to the solution of this problem. Therefore, the underground structure-country rock dynamic interaction may be described by dynamic equations of flexural members of thin plate and thick plate, which express linear and country rock respectively. The interaction force between the liner and country rock is expressed as contacting pressure function q(x, l). By solving system of simultaneous equations, the analytical solution for the dynamic analysis of arch-straight liner including elastic half space interaction effect is given and the analytical expression of function q(x, t) is obtained. This analytic solution will contribute to the study of some substantive problems of underground structure-medium dynamic interaction theoretically. (Instutute of Engineering Mechanics, Academia Sinica)     

Energy element and its application in the dynamic calculation of continuous medium

The present paper which discusses the problem related to the combination of the finite difference method and the finite element method, describes an energy element calculating mode including the special features of the above two methods.     

地下结构与岩体动力相互作用的一种解析解

本文根据大量试验和数值分析结果指出:在侧向爆荷下岩洞在厚度为跨度三分之一围岩中具有厚壁受弯构件的力学特征,而在该围岩区外即基本上接近自由场应力状态,并可用厚板理论方程在自由场压力的外载下进行求解.因此,地下结构与围岩动力相互作用,可用分别代表衬砌及介质的基于薄板与厚板理论的受弯构件动力方程宋描述.围岩和衬砌二者之间的相互作用力用接触压力函数q(x,t)加以联系.通过解一组联立方程,给出了计入与弹性半空间相互作用效应的直墙拱顶衬砌时动力分析的解析解,同时列出了函数q(x,t)的解析表达式. 本解析解将有助于从理论上探讨地下结构与介质动力共同作用的一些本质问题.     

A semi-analytical method for structure-internal liquid interaction problems

A composite structure-internal liquid element is proposed in this paper. Through the use of analytical functions in two orthogonal directions, the three-dimensional problem of coupled structure-internal liquid vibration is reduced to a one-dimensional one, resulting in a drastic reduction in computing efforts.Cylindrical and conical frastum composite elements are proposed to suit different problems, and examples are presented to demonstrate the accuracy of the method.     

弹性薄板弯曲问题的边界轮廓法

导出了弹性薄板弯曲问题边界积分方程的另一种形式,基于这种方程,提出了平板弯曲问题的边界轮廓法,讨论了三次边界单元边界轮廓法的计算列式,并给出了计算内力的边界轮廓法方程。该法无需进行数值积分计算,完全避免了角点问题和奇异积分计算。给出的算例,与解析解相比较,证实该方法的有效性。     

时变固体力学的黏弹性解

基于时变力学的对应性原理,建立一种黏弹性时变力学的一般性解法,适用于一类时变力学问题的求解。     

Boundary integral equations of unique solutions in elasticity

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无限粘弹性平面中孔洞扩展的时变力学解析解

从粘弹性时变力学基本方程出发,针对Maxwell本构模型,导出了双向等压下粘弹性平面中圆孔半径任意规律扩展时的时变力学解析解.在内径线性时变时,其结果与用对应原理法得出的解相同,其解的可靠性得到验证.与对应原理法相比,文中的结果适用于半径任意时变情况,更具一般性.