软土深层搅拌桩的水泥土抗腐蚀性室内试验

结合深港西部通道填海区深层搅拌桩在滨海地下水环境中施工的需要,对水泥土在自来水、地下水、海水及Na2SO4溶液环境下的抗腐蚀性进行了室内研究,研究表明以纯水泥为固化剂的水泥土在腐蚀性地下水环境中的抗腐蚀性能较差,增加矿渣、粉煤灰的含量,能增强水泥土抗腐蚀性;分析了固化剂中矿渣、粉煤灰掺入量对水泥土抗压强度及抗腐蚀性的影响规律,即固化剂掺入比不变的情况下,用矿渣、粉煤灰替代部分水泥能大幅度提高水泥土的抗压强度,同时改善其抗腐蚀性;得出了抗腐蚀性能良好的水泥土配方,即矿渣、粉煤灰的质量占固化剂的40%～60%,可供同类工程借鉴.

Laboratory Experiment of the Anticorrosion of Cement Stabilized Soft Soil in Deep Mixing Pile

For the need of deep mixing pile installation of western channels of Shenzhen lough in seawater, the paper designed laboratory experiments on anticorrosion ability of cement soil in the condition of water, corrosive groundwater, seawater and solution with w(Na2SO4)=1. 5%, respectively. The study illustrates that cement soil with single harden agent cement has poor anticorrosion in corrosive seawater. Increasing the percentage of cinder and fly ash in harden agent would enhance the anticorrosion of cement soil. Also, the study has established the relationship between percentage of cinder and fly ash in harden agent and compressive strength and anticorrosion of cement soil. It is showed that when the percentage of harden a gent keeps unaltered,substituting some amount of cinder and fly ash for cement would increase the compressive strength remarkably and also improve anticorrosion ability. Then,the optimal anticorrosive formula for cement soil is presented. When cinder and fly ash accounts for 40%-60% in harden agent,the need of both compressive strength and anticorrosion ability could be satisfied. This study provides feasible instructions for similar projects.