水泥搅拌桩和砂桩在真空预压防护工程中应用与分析

基于南沙港区格栅水泥搅拌桩和砂桩联合防护真空预压影响区内高压电缆沟的工程实例,分析了该真空预压影响区的防护方案,对比试验研究影响区防护和未防护断面的表层位移、深层侧向位移和地层中孔隙水压力变化规律;位移测试结果表明该防护方案是有效的,保护了高压电缆沟的安全;地层中孔压变化结果表明深层格栅水泥搅拌桩周围土体有渗流发生,该地层土体中孔隙水压力降低及地下水渗流使土中有效应力改变是周围土体发生变形的主要原因。

Analysis and application of cement-mixed piles and sand piles to protection projects of soft ground improved by vacuum preloading

Based on the application of gridiron cement-mixed piles and sand piles to protection of high-voltage cable channel in soft ground improved with vacuum preloading technique, protection project was analyzed. Some contrast were performed on protected and non-protected sections by vacuum preloading to observe surface deformation, deep lateral displacement and pore water pressure in stratum. It was shown that the protection project was effective and the high-voltage cable channel was safe. Variation of pore pressure water demonstrated that there was seepage through gridiron cement-mixed piles in deep soil. The change in effective stresses resulted from falling of pore water pressure and ground water seepage was the main factor inducing deformation of soft ground by vacuum preloading.