胶结坝胶结砂砾石层面原位剪切试验研究

Experimental study of in-situ shear of cemented sand and gravel rocks layers

西江胶结坝为充分利用工程弃渣料,将弱风化料和强风化料均作为筑坝材料。胶结强风化料筑坝,其层间抗剪性能关乎大坝抗滑稳定,现场开展层间原位抗剪试验研究旨在得到抗剪断参数,验证大坝抗滑稳定。本文按照现行规范,对两组胶结砂砾石试件开展了原位抗剪试验。试验得到的两组胶结砂砾石层间抗剪断参数,经复核计算,大坝均是稳定的。试验还表明强风化料胶结砂砾石多为本体和层面混合剪断,弱风化料胶结砂砾石多为层面剪断;强风化料胶结砂砾石内摩擦角f′较大,抗剪断黏聚力c′较小。胶结砂砾石试件剪切变形属于脆性材料特性。本次试验成果可供千枚状绢云母板岩及变余层凝灰岩地区参考。

In order to make full use of engineering slag,both weak weathering material and strong weathering materials are used as dam-building materials In the construction of Xijiang Cemented Material Dam.Interlinear shear behavior of cemented strongly weathered materials is related to the stability of dam against sliding.The in-situ interlinear shear test was carried out to obtain the shear parameters and verify the anti-sliding stability of the dam.In this paper,in-situ shear tests of these two groups of cemented sand and gravel specimens were carried out according to the current code.According to the interlinear shear parameters of the test,the dam is stable after verification and calculation.The results also show that,the shear failure surface of cemented gravel with strong weathering material is mostly mixed shear surface,and the weak weathering material is mostly plane shear.The internal friction angle f’of the strong weathered material cemented sand and gravel is large,and the shear cohesion c’is small.Shear deformation of cemented sand and gravel specimen belongs to brittle material characteristics.The results of this test can be used for reference in the area of thousand-shaped sericite slate and palimpsest tuff.