高土石围堰复合土工膜与防渗墙联接型式研究

发布时间：2018-03-05 16:12

本文选题：高土石围堰　切入点：复合土工膜　出处：《长江科学院院报》2017年02期 　论文类型：期刊论文

【摘要】：复合土工膜与防渗墙联合作为围堰防渗体系,其联接部位处容易产生破裂而存在安全隐患,接头部位是该防渗体系的薄弱环节。因而,需开展土工膜与防渗墙联接型式的研究,避免复合土工膜因防渗墙与堰体的变形差异而产生破坏,确保围堰整个防渗体系的安全。以西部某水电站高土石围堰为例,采用有限元分析方法,重点研究了防渗墙与堰体联接部位土工膜的受力及变形规律,以及深厚覆盖层上高土石围堰的整体应力变形规律。结果表明:当土工膜与防渗墙之间采用不同联接型式时,对堰体和防渗墙的应力变形影响较小,但对防渗墙与堰体间位移差异和土工膜应变有显著影响。如土工膜采用平直铺设,则沉降错动会使得接头部分土工膜产生较大的拉应变。随着土工膜平铺段位置的抬高,接头处的土工膜应变大幅减小,受力较为有利。由此可知,将土工膜竖直抬高一定距离后再进行平直铺设是合理的,最终应结合室内拉拔试验成果,确定上覆土层的临界厚度。
[Abstract]:Composite geomembrane and impervious wall are combined as cofferdam impervious system, and the connection part of the composite geomembrane and impervious wall is easy to break and there is a hidden danger of safety. The joint part is the weak link of the impervious system. Therefore, it is necessary to study the connection type of geomembrane and impervious wall. To avoid the damage of composite geomembrane due to the deformation difference between impervious wall and Weir body, and to ensure the safety of the whole impervious system of cofferdam, taking the high earth and rock cofferdam of a hydropower station in the west as an example, the finite element analysis method is adopted. The stress and deformation law of geomembrane in the connection between impermeable wall and Weir body and the integral stress and deformation law of high earth and rock cofferdam on deep overburden are studied. The results show that when different connection types are adopted between geomembrane and impervious wall, It has little effect on stress and deformation of Weir and impermeable wall, but has significant effect on the difference of displacement and strain of geomembrane between impermeable wall and Weir. With the elevation of the position of the geomembrane flat section, the geomembrane strain at the joint decreases significantly, and the force is more favorable. It is reasonable to raise the geomembrane vertically for a certain distance and then lay flat. Finally, the critical thickness of the overlying soil should be determined in combination with the results of indoor drawing test.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;中国长江三峡集团公司;长江勘测规划设计研究院;
【基金】：国家自然科学基金项目(51309029,51509019) 中央级科研院所基本科研业务费项目(CKSF2016030/YT)
【分类号】：TV543.8;TV49

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