南京地铁4号线二期工程滨江站—龙江区间中段江心洲风井工程地表存在淤泥质黏土和较厚高承压水粉砂层，下部覆盖高强度砂砾岩层，地连墙施工时若泥浆参数选择不当则难以起到护壁效果进而发生塌孔或缩孔情况。提高泥浆重度是增大槽壁稳定性安全系数的最直接方式，但同时也会增加工程成本。为探明淤泥覆盖下高承压水砂层中地连墙成槽作业时最优的泥浆参数，分析并评价该地质条件下的成槽质量，采用泥浆护壁的抛物柱法三维模型对泥浆参数进行计算，并通过试成槽试验和超声波检测对计算结果进行验证，最终选择出合适的泥浆配比。研究结果证明泥浆黏度为60 s，泥浆比重为1.07 g/cm³时可以保证成槽稳定性系数为1.5，结果可为类似工程提供参考。

In the middle section of the Jiangxinzhou wind shaft project within the Nanjing Metro Line 4 Phase II project, spanning from Binjiang Station to the Longjiang interval, a geological composition is encountered consisting of silty clay and a substantial layer of high-pressure water-saturated sands. Below this, there exists a high-strength gravel layer. In the context of ground connection wall construction, failure to select appropriate mud parameters may result in a compromised wall protection effect, leading to potential wall collapse or hole shrinkage. The most direct approach to enhance wall stability is by increasing the mud weight, albeit at a significant escalation in project cost. To ascertain the optimal mud parameters for trenching operations beneath the high-pressure water-saturated sand layer overlain by silt and to conduct an analysis and evaluation of trenching quality under these geological conditions, a parabolic column method three-dimensional model of the mud wall protection system was employed in this study. This model facilitates the calculation of mud parameters, with the subsequent validation of results through trial trenching tests and ultrasonic testing. Ultimately, a suitable mud ratio was chosen based on the research findings. The research outcomes substantiate that a mud viscosity of 60 s and a specific gravity of 1.07 g/cm³ can ensure a stability factor of 1.5. These findings provide valuable reference points for similar projects and hold potential significance for future research in this domain.