泥岩风化料在龙虎水库大坝防渗心墙填筑中的应用

Application of mudstone weathered material in the filling of impervious core wall for Longhu Reservoir Dam

为了解龙虎水库大坝防渗心墙料(当地泥岩风化料)的压实情况,以便为大坝的填筑施工提供科学依据,对泥岩风化料进行现场碾压试验。试验结果表明,由于料源母岩以软岩为主,在碾压和击实过程中砾石破碎率大于30%,压实性满足设计要求;按碾压试验确定的参数施工,防渗性能满足设计要求;料场天然含水率高于且接近最优含水率,施工时不用调整含水率可直接上坝,但要立采混合均匀方可进行填筑;该土料渗透系数小于5×10-6cm/s,具有较高的抗渗透变形稳定性。经复核试验验证及蓄水检验,当地泥岩风化料在龙虎水库大坝防渗心墙填筑中的应用是成功的。

In order to provide a scientifis basis for construction of the Longhu Dam, filed compaction tests were carried out to study the compactibility of the local mudstone weathered material used in the filling of the impervious core wall. Tests results show that, the parent rock of the material is mainly soft rock and its gravel breakup rate is larger than 30% during the roller compaction process, so the compactibility of the mudstone weathered material can meet the design requirements of the impervious core wall; the permeability of the impervious core wall can be satisfied by implementing the construction according to parameters obtained from field compaction tests; the natural water content of the material is slightly higher than the optimal moisture content, hence, the material can be directly used in the dam filling after homogeneous mixing, without adjustment of water content of the material; the permeability coefficient of the material is lower than 5 x 10-rcm/s, and the safety factor of seepage stability of the impervious core wall is relatively high. Hence, it is verified by filed compaction tests that the application of mudstone weathered material in the filling of an impervious core wall for Longhu Dam is successful.