工程地质力学及其应用中的若干问题

SOME ISSUES IN ENGINEERING GEOMECHANICS AND ITS APPLICATIONS

工程地质力学是以工程为目的研究地质体变形破坏规律的科学。地质体具有非连续、非均匀、流–固耦合以及未知的初始状态的特性,工程地质力学的关键科学问题包括如何判断地质体的当前状态、描述地质体的力学特性以及分析地质体由连续到非连续的演化过程。工程地质力学研究应当以地学为基础、力学为手段、工程为目的,迫切需要解决的工程问题包括探测地质体的几何和力学特性,给出地质体稳定性的分析方法、地质工程设计依据以及地质灾害的预测预报方法。无论是模型实验还是模拟实验的结果能否回答工程问题取决于对地质条件的认知程度,但是,实验研究可以作为验证数值模拟结果的有力工具;地质调查和现场测量是工程地质力学必不可少的组成部分,地质体的力学分类体现了地学的基础作用,可实现地质环境描述定量化。针对工程需求建立力学模型可主要考虑含结构面岩体、土石混合体以及地质中裂隙流和岩土体的相互作用;实验室岩块实验的试样尺寸应作为地质体多尺度计算模型中的基本尺度。工程地质力学的主要研究内容应当包括给出关键的力学测量参数、研究获得这些参数的方法及相关的仪器;在提出和完善力学模型的同时,应更加注重新的计算方法的验证以及工程应用研究。

Engineering geomechanics is a subject aiming at investigating generalized deformation and failure processes of geological body for engineering problems. Due to geological body inherent characteristics of discontinuity, inhomogeneity, coupled fluid-solid and unknown initial state, key scientific issues in engineering geomechanics are how to judge current state of geological body, how to describe mechanical properties of geological body, and how to simulate the evolution from continuous to discontinuous failure process. Researches in the area of engineering geomechanics should take geology as the foundation, take mechanics as the analytical tool, and its aim should face engineering. The engineering problems to be solved include investigating the geometrical and mechanical properties of geological body, developing the analytical method for geological body stability, and providing the design basis for geological engineering as well as the prediction and forecast scheme. Whether model experiments or simulation results of experiment can answer engineering questions is determined by the extent to identification of geological conditions. But experimental studies can be recognized as a powerful tool to verify the results of numerical simulation： and geological investigation and spot survey are indispensable parts in engineering geomechanics. The mechanical classification of geological body embodies the underlying role of geology, and is able to quantitatively represent the geological environments. The construction of mechanical models, which meets engineering requirement, needs to consider rock masses with discontinuity, rock and soil aggregates as well as the interaction between flow in fractured rock and rock masses. The extraction of measurement parameters, development of approaches to obtain these parameters, and research on relevant test devices require the participation of geomechanics. While present mechanical models are improved or new models are developed, more attention should be paid to the verification and application of new methods.