复杂地层条件TRD水泥土搅拌墙抗渗性能分析

Seepage Characterization of Slurry Walls Constructed by TRD Method in Complex Soil Strata

超深等厚度水泥土搅拌墙作为深基坑隔水帷幕,墙体抗渗性能和强度的好坏是确保基坑安全实施和周边环境安全的关键。基于多项复杂地质条件和环境条件下等厚度水泥土搅拌墙的基坑工程实践,通过室内试验或现场原位试验对不同深度水泥土搅拌墙墙体抗渗性能进行系统的统计分析研究,并从实施效果角度进一步验证各种地层中墙体的成墙质量和隔水效果。试验结果表明,墙体渗透系数较原状土层尤其是粉土和砂土层降低显著,在深厚粉土和砂性土层中墙体渗透系数均达到10^(-6) cm/s^10^(-8) cm/s数量级;实施效果也表明,采用等厚度水泥土搅拌墙作为深基坑隔水帷幕,有效隔断坑内外地下水尤其是深厚砂层承压水的水力联系,水泥土搅拌墙抗渗性能良好。

The seepage and strength properties for the Trenching cutting and Remixing Deep（TRD）wall as the slurry wall are critical for a safe foundation excavation projects as well as minimizing the adverse impact to the adjacent environment.This paper presents the statistical analysis results of the laboratory and in-situ tests on the seepage properties of the soil-mixed the walls.The seepage properties and the construction quality of the slurry walls constructed with TRD method were examined from the constructability point of view.The test results indicate that,the seepage properties of the constructed TRD wall are significantly reduced,compared with the original in-situ soils,especially,silty and sandy soils.The tested coefficient of permeability of slurry wall in silty and sand soils is between 10^（-6） cm/s and 10^（-8） cm/s.The construction results show that the TRD constructed slurry can effectively separate the connections between the excavated area and soil behind the wall.It can also separate the hydraulic link of the artesian groundwater in the deep thick sandy stratum.