李元霞, 孙进忠, 杜明性, 田爱苹, 郑卫锋. 2011: 北京晓幼营板理化岩体结构面强度的原位测试. 工程地质学报, 19(1): 129-136.
    引用本文: 李元霞, 孙进忠, 杜明性, 田爱苹, 郑卫锋. 2011: 北京晓幼营板理化岩体结构面强度的原位测试. 工程地质学报, 19(1): 129-136.
    LI Yuanxia, SUN Jinzhong, DU Mingxing, TIAN Aiping, ZHENG Weifeng. 2011: IN-SITU TEST FOR SHEAR STRENGTH OF STRUCTURE PLANE IN PLATY ROCK MASS AT XIAOYOUYING,BEIJING. JOURNAL OF ENGINEERING GEOLOGY, 19(1): 129-136.
    Citation: LI Yuanxia, SUN Jinzhong, DU Mingxing, TIAN Aiping, ZHENG Weifeng. 2011: IN-SITU TEST FOR SHEAR STRENGTH OF STRUCTURE PLANE IN PLATY ROCK MASS AT XIAOYOUYING,BEIJING. JOURNAL OF ENGINEERING GEOLOGY, 19(1): 129-136.

    北京晓幼营板理化岩体结构面强度的原位测试

    IN-SITU TEST FOR SHEAR STRENGTH OF STRUCTURE PLANE IN PLATY ROCK MASS AT XIAOYOUYING,BEIJING

    • 摘要: 岩体强度很大程度上取决于结构面的强度,板理化岩体尤其如此。通过原位测试直接获得岩体结构面的强度参数对于岩体稳定性分析和工程设计都具有重要意义。为了解板理化岩体板理结构面的强度性质,选择北京房山区晓幼营白云质板理化岩体进行了结构面强度的原位测试研究。鉴于传统岩体原位直剪试验成本高和操作难的情况,在掌握北京地区构造应力资料的基础上,在试验中考虑岩体中板理结构面的产状与构造应力方向的关系,提出了一套利用地应力提供原位试体剪切面法向力的测试分析方法:开挖出不同方向、不同解除状态的3个试体(试坑); 试坑中两个平行的解除面与原岩之间形成一定距离的空间,自然构成了施加水平试验荷载的反力框架,从而免除了传统试验中笨重的试验反力装置。由于解除面组合的变化,试体受到的构造应力状态有相应的变化,与试验荷载叠加后在预定剪切面上形成了不同大小法向力和切向力。上述方法免除了笨重的反力装置,取得了一定的实验效果,确定了被测岩体结构面的强度参数:黏聚力c和摩擦角,对原位岩体结构面强度测试方法进行了一次有益的新尝试,得到的岩体结构面的强度参数为类似板岩地区大型输电线路塔杆地基设计及岩体稳定性分析提供了参考。

       

      Abstract: Strength of rock mass is largely determined by the strength of structure planes in the rock mass. This is especially true to platy rock mass.It is significant to get the strength parameters of structure planes in the rock mass directly by in-situ test both for the stability analysis of rock mass and for engineering design.In order to understand the strength property of platy rock mass,in-situ tests for the strength of the structure plane in dolomite platy rock mass at Xiaoyouying in Fangshan District of Beijing are carried out.Traditional in-situ tests will result in a high cost,and bring more difficulties for the shear strength of rock mass.To get rid of the heavy reaction frame,according to the relationship between the attitude of platy planes and the direction of tectonic stress in the rock mass,three test rock blocks,laterally disconnected from their parent rock in different forms,are dug out vertically on the horizontal ground of the test site.Beside two parallel vertical free surfaces,a certain free room is left between test block and its parent rock.This room is just a reaction frame for loading,where a jack and steel pads can be put and horizontal test loads can be applied vertically to the free surface of the test block.This makes the test get rid of cumbersome reaction equipment totally.The state of the tectonic stress in the test block changes with the forms of block disconnection from its parent rock and the varied tectonic stresses in different states,adding upon the stresses caused by horizontal test loads,forms different normal and tangential stresses in the pre-concerted shear plane at last.By means of the test method explained above,and based on the data of the local tectonic stress in Beijing territory,a pretty good result has resulted from the in-situ test for the shear strength(c,)of platy planes in the dolomite platy rock mass at Xiaoyouying in Fangshan district of Beijing.The strength parameter will be a helpful reference for the design of extra high voltage network foundation and for the stability analysis of engineering rock masses in mountain areas with similar platy rock mass.

       

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