大坝心墙接触粘土工程特性试验研究

以长河坝水电站心墙砾质土高坝接触粘土开采质量控制为例,探讨了接触粘土不同颗粒分析方法和不同击实试验方法对检测成果的影响。通过对填土压实度及含水率的系列试验研究,提出了临界压实度概念,建议压实度宜控制在98%及以上。研究得出心墙接触粘土填筑采用宁潮勿干的原则,可增加心墙接触粘土的塑性和粘性、减小渗透及水库蓄水后大坝沉降、提高抗接触冲刷能力。研究成果对了解粘土工程性质、指导设计和施工具有一定工程意义。

Test Study for Engineering Characteristics of Contact Clay of Dam Core Wall

In this paper,taking the quality control for contact clay mining of the high rock-fill dam with gravelly soil core wall in Changheba Hydropower Station for example,the effects of different particle analysis and compaction test methods on inspection result are studied.By further experimental study of compaction and moisture content,the concept of critical compaction is proposed,and it is suggested that the compaction should be controlled to 98% or higher.It is also concluded here that the filling of the contact clay of core wall should use higher moisture content rather than a lower one,which could increase the plasticity and viscosity of the contact clay of core wall,decrease the infiltration and dam settlement after water storage,and increase the contact erosion resistibility.The research achievement is of a certain engineering significance for studying the engineering property of clay and guiding the design and construction.