于桥水库大坝地震液化判别和动力分析

Liquefaction Evaluation and Dynamic Analysis of Dams of Yuqiao Reservoir Under Earthquakes

地震作用下水库大坝坝体填土和坝基砂液化、坝坡失稳是大坝安全运行重点。针对天津于桥水库主坝最大断面1+150进行了大坝地震危险性分析,采用现场标贯试验和室内动三轴试验对大坝水中倒土、坝基中粉质黏土、粉砂层和沙砾石层进行了地震液化判别;进行了有效应力动力法数值计算,结果表明:地震作用下,上游坝体填土在库水位以下部分的坝坡浅层在一定范围内可能液化,坝基砂层局部液化,沙砾石层也可能液化;大坝可能存在裂缝和局部隆起,但大坝整体是稳定的,可适当培厚。

The filling silt in the dam and sand under the dam foundation of Yuqiao Reservoir can be easily liquefied when an earthquake happens.It＇s the key of dam safety management.In this paper,the most dangerous section 1＋150is analyzed seismic hazard of the dam.The liquefaction evaluation of silt and sand is made according to the results of the standard penetration tests in-situ and dynamic tri-axial tests indoor;their results are also compared.The conclusions are drawn about the dam stability with the effective dynamic stress method：some sections of the dam would be liquefied under earthquake including the filling silt under upstream shallow water of the dam,the sand,even the gravel under the dam foundation.The dam could be partly cracked and upheaval,but it＇s still stable on the whole and stone materials can be used to press the slope.