摘要
建造在透水的深覆盖层上的土石坝,坝基常设有混凝土防渗墙,如何正确地确定防渗墙的应力是坝工设计的难点.本文根据已完成的墙项覆土压力的槽内试验和塑流理论,推导了墙顶覆土压力的公式;提出由非线性土体单元、线性梁单元、摩擦接触单元等3种单元组成的有限元法并计算了瀑布沟和小浪底等土石坝及其防渗墙,得出坝基混凝土防渗墙是偏心受压构件以及墙与土之间和土本身的抗剪强度决定墙的竖直荷载等结论.作者认为:根据墙周围土的塑性极限分析,采用一般通用的高标号混凝土,就能满足高土石坝下数十米深覆盖层中防渗墙的强度要求,无须改用抗渗性能差的掺膨润土的混凝土软墙.
For deep and pervious soil foundation under earth-rockfill dam, a concrete diaphragm wall must be provided to control seepage. In the present paper, based on our experiments of the overburden earth pressure at the top of the wall and theory of plasticity, the formula of the overburden earth pressure at the top of wall has been derived. The stress of the earth-rockfill dam with a concrete diaphragm wall is analysed by FEM, in the analysis, three kinds of elements have been used. The nonlinear soil elements are used to model the dam and the foundaton, the beam elements are used to model wall, and the friction contact elements are installed between the wall and the soil.Analysis of Pubugou Dam and Xiaolangdi Dam has proved that the concrete diaphragm wall, being subjected to vertical compression and moment, is an eccentrically compressed member. The vertical axial force in the wall depends upon the shear strength of the soil surrounding the walJ, and the stress in the diaphragm wall can be sustained by common concrete.
出处
《水利学报》
EI
CSCD
北大核心
1990年第4期11-21,共11页
Journal of Hydraulic Engineering
