钙质胶结地层灌注桩护壁泥浆渗透性能

Permeability of wall-protecting mud with calcite-cemented formation cast-in-place pile

针对存在钙质胶结地层地区灌注桩的施工中出现的塌孔问题,提出了采用环向加压状态下泥浆成膜试验装置,对不同胶结程度的地层进行成膜试验和环向加压的泥浆渗透试验,分析护壁泥浆对钙质胶结地层的适应性.结果表明,在相同压力持续时间、泥浆压力条件下,优化后的泥浆在钙质胶结地层能有效提高成孔质量,保证孔壁稳定性.经过护壁泥浆渗透性能试验研究可知,优化后的护壁泥浆可有效改善钙质胶结地层施工中的塌孔问题.

Aiming at the hole collapse problem of cast-in-place pile in calcite-cemented formation region during construction engineering, a toroidal pressure mud film test device was used to perform the film formation test with different degrees of consolidation and toroidal pressure mud permeation, and the adaptability of wall-protecting mud in the calcite-cemented formation was analyzed. The experimental results show that the optimized mud can effectively improve the hole quality of calcite-cemented formation and ensure the stability of hole wall under the same pressure duration and mud pressure. It is proved that the optimized wall-protecting mud can effectively alleviate the hole collapse problem for construction in calcite-cemented formation.