汉江兴隆水利枢纽泄水闸地基处理设计

汉江兴隆水利枢纽泄水闸深厚粉细砂土层地基厚约25 m。为解决地基沉降量大与饱和砂土震动液化问题，经对强夯法、振冲法和水泥土搅拌桩法等处理方案比选后，决定采用水泥土搅拌桩对地基进行处理。现有搅拌桩工程实例大多是处理摩阻力较小的黏性软土，对于处理摩阻力大和存在流动地下水的粉细砂层尚属少见。为此，对水泥土搅拌桩进行了室内和现场试验研究，证实了搅拌桩适宜于处理兴隆泄水闸粉细砂地基。搅拌桩采取格栅式布置，置换率约20％。施工完成后的搅拌桩质量检测全部合格，变形监测结果表明，沉降量控制满足设计要求。

Design of sluice foundation treatment of Xinglong Hydrojunction Project on Hanjiang River

The thickness of the sluice foundation of Xinglong Hydrojunction Project on Hanjiang River, a deep fine sand layer, is 25 m. To solve the liquefaction problem of saturated sand and large settlement of the foundation, the foundation was treated by using cement-soil mixing pile rather than the dynamic consolidation or vibroflotation method through comparison. In the current cases of mixing pile, the viscous soft soil with small frictional resistance are treated; however, the treatment of fine sand layer with large frictional resistance and running groundwater are rare. Therefore, the laboratory experiment and in-situ test of cement-soil mixing pile was conducted, which proved that this mixing pile is suitable for the treatment of the sluice foundation of Xinglong Hydrojunction Project. The piles are arranged in grid with the replacement rate of 20%. The quality of the mixing pile meets the requirement and the deformation monitoring shows that the settlement control meets the design requirement.