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为了调查黄壁庄水库副坝频发塌陷事故的原因,从防渗墙槽壁稳定性角度研究了槽壁稳定性与护壁泥浆重度之间的关系,分析了第六次塌陷前的测试试验结果,并在多种因素共同作用下分析了黄壁庄水库副坝的塌陷机理。结果表明,由于护壁泥浆重度小于设计临界重度,使得槽壁失稳;同时泥浆水渗透到周围非饱和土层,引起土层地下水位上升,尤其是坝基下面的粉土层,在冲击成槽的施工振动、地下水位上升、含水率增加等多种因素的作用下逐渐液化,从而造成承载力降低;另外由于事先未发现基岩中存在溶洞,当成槽钻孔揭穿溶洞时,槽体内的护壁泥浆迅速下沉,槽壁的稳定急剧破坏,致使槽壁完全塌陷。
In order to investigate the causes of frequent subsidence in the secondary dam of Huangbizhuang Reservoir, the relationship between the stability of the tank wall and the weight of protective slurry was studied from the perspective of the stability of the cut-off wall, and the results of the test before the sixth subsidence were analyzed. Under the combined action of many factors, the subsidence mechanism of Huangbizhuang reservoir was analyzed. The results show that the mud wall water is not stable due to the heavyness of the protective wall mud being less than the critical critical height. At the same time, the muddy water infiltrates into the surrounding unsaturated soil layer, causing the groundwater table to rise, especially the silt layer beneath the foundation. Construction vibration, groundwater level rise, moisture content increased under the action of a variety of factors such as the gradual liquefaction, resulting in reduced bearing capacity; the other as previously found no bedrock cave, as a groove drilling hole when exposed, the tank body wall mud Rapidly sinking, the stability of the tank wall sharply destroyed, resulting in complete collapse of the tank wall.