裂隙对四分量钻孔应力–应变观测影响的数值模拟分析  

Numerical simulation analysis of effects of cracks on 4-component borehole observation of stress-strain

作　　者：姚瑞[1] 杨树新[1] 王迪[1,2] 

机构地区：[1]中国地震局地壳应力研究所,北京100085 [2]北方科技信息研究所,北京100089

出　　处：《岩土工程学报》2016年第2期331-335,共5页Chinese Journal of Geotechnical Engineering

基　　金：中国地震局地壳应力研究所中央级公益性科研院所基本科研业务专项(ZDJ2013-14);2014年地震监测台网运行经常性项目资助

摘　　要：钻孔围岩中存在裂隙是导致钻孔应力–应变观测中测试值不满足自洽关系的原因之一,但缺乏理论依据。建立若干个二维有限元模型,通过模拟计算相邻45°的各元件位移,定性地研究裂隙与最大水平应力的角度、最大水平应力与最小水平应力比值、裂隙与孔壁距离、长度、宽度和材料属性几种典型要素对四分量钻孔应力–应变观测的影响。结果显示,几种因素对钻孔应力–应变观测都有比较明显的影响,当裂隙延展方向与最小水平应力方向一致或最大水平应力与最小水平应力比值越大、裂隙与孔壁距离越近、裂隙尺寸越大、裂隙的材料属性与围岩的差距越大时,裂隙的存在对观测的影响越明显。The existence of cracks in wall rock of borehole is one of the reasons for the fact that the test values do not meet the self-consistent relationship in borehole observation of stress-strain. However, there are few theoretical researches supporting the fact. The displacements of adjacent components of 45° are calculated using a series of two-dimensional finite element models to qualitatively study the effects of different kinds of cracks on observation. The factors include angles between cracks and the maximum horizontal stresses, ratios of the maximum to the minimum horizontal stresses, distances of cracks and the borehole, length, width and material properties of the cracks. The results show that all the factors have more obvious effects on the borehole stress-strain observation when the crack extension direction is in accordance with the minimum horizontal stress direction or when the ratios of the maximum to the minimum horizontal stresses are larger, the cracks and the borehole are closer, the sizes of cracks are larger, and the differences of the material properties of the cracks and the hole wall are larger.

关 键 词：裂隙 四分量钻孔 应力–应变观测 数值模拟 

分 类 号：TU472.33[建筑科学—结构工程]