软岩砾石料填筑防渗心墙的工程应用研究

Engineering application of soft gravel material in filling of impervious core wall

云南省楚雄州青山嘴水库大坝防渗心墙料以当地沙邑村砾石料为主,由于料源构成复杂、物理性能存在较大差异,为此进行了大量的试验研究。研究结果表明,由于料源母岩以软岩为主,在碾压和击实过程中,砾石破碎率较高,无明显砾石土的含砾量特征值(P5Ⅰ和P5Ⅱ),压实最大干密度及最优含水率不需作校正,压实度满足设计要求;通过控制上坝料砾石含量、细粒含量及砂岩含量,并按碾压试验确定的参数施工,防渗性能满足设计要求。针对该土料崩解速度快、崩解彻底的问题,通过严格控制反滤料的级配,心墙料得到了很好的保护,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,证明此种砾石土料在青山嘴水库工程上的应用是成功的。

The filling material of core wall of Qingshanzui Reservoir in Chuxiong City of Yunnan Province was mainly the gravel material from Shayi material yard,which was characterized by complicated material sources,large variation of material features.The applicability was verified by a large amount of test studies.The results showed that as the parent rock was soft rock,which was likely to shatter during compaction and filling,and no obvious gravel content feature value was found;so the correction of compacted maximum dry density and optimum moisture content was not necessary and the compactness met the design requirement.The impervious requirements could be satisfied by controlling the gravel content,fine grain content,sandstone content in filling material and implementing the construction according to parameters obtained by filling tests.By controlling the grade of filter material,the problem of quick and thoroughgoing disintegration of the material was solved and therefore the high anti-pervious stability of the core wall was achieved.