水泥改良土电阻率随压载变化特性试验研究

高涛¹，孙建军¹，李帅²，张永壮^3*，吴鸿芮^3*，刘冰冰³

1.山东省交通规划设计院集团有限公司，山东济南250101；2.山东港口渤海湾港集团有限公司，山东潍坊261000；

3.山东交通学院交通土建工程学院，山东济南250357

摘要：为研究不同含水率下水泥改良土的抗剪强度及电阻率特性，制备含水率分别为7.7%、9.7%、11.7%、13.7%、15.7%、17.7%、19.7%的水泥改良土试件，水泥在水泥改良土中的质量分数为8%，对试件进行剪切试验，分别施加垂直压力100、200、300、400 kPa，研究有压和无压条件下水泥改良土抗剪强度变化规律及电阻率响应特性。结果表明：1）无压条件下不同含水率试件的黏聚力和内摩擦角均与初始电阻率存在二次函数关系，拟合曲线决定系数较大，表明采用电阻率法评估抗剪强度特性可行；试件的抗剪强度与破坏电阻率间均近似呈线性关系，抗剪强度随电阻率的增大而减小；随垂直压力的增大，试件的峰值剪应力整体呈增大趋势，随含水率的增大，峰值剪应力先增大后减小。2）有压条件下试件的含水率与初始电阻率、破坏电阻率均呈负相关指数函数关系；随垂直应力的增大，不同含水率下试件的破坏电阻率降幅减小；试件的破坏电阻率随含水率的增大而减小；不同含水率下，试件的破坏电阻率随垂直压力的增大整体呈减小趋势。

关键词：水泥改良土；电阻率；抗剪性能；试验研究

Experimental research on the variation characteristics of resistivity of cement-improved soil with changes in load

GAO Tao¹, SUN Jianjun1, LI Shuai², ZHANG Yongzhuang^3*, WU Hongrui^3*, LIU Bingbing³

1. Shandong Provincial Communications Planning and Design Institute Group Co., Ltd., Jinan 250101, China;

2. Shandong Port Bohai Bay Port Group Co., Ltd., Weifang 261000, China;

3. School of Civil Engineering, Shandong Jiaotong University, Jinan 250357, China

Abstract: To investigate the shear strength and electrical resistivity characteristics of cement-stabilized soil under varying moisture contents, specimens were prepared with moisture contents of 7.7%, 9.7%, 11.7%, 13.7%, 15.7%, 17.7%, and 19.7%, and a fixed cement content of 8%. Direct shear tests were conducted under vertical pressures of 100, 200, 300, and 400 kPa to examine the variation patterns of shear strength and resistivity responses under both unconfined and confined conditions. The results indicate that under unconfined conditions, both cohesion and internal friction angle at different moisture contents exhibit quadratic relationships with the initial resistivity. The fitted curves show high coefficients of determination, confirming the feasibility of assessing shear strength based on resistivity measurements. A nearly linear correlation is observed between shear strength and failure resistivity, where shear strength decreases as failure resistivity increases. With increasing vertical pressure, the peak shear stress of the specimens generally increased. As the moisture content increased, the peak shear stress first increased and then decreased. Under confined conditions, both initial and failure resistivity values exhibited negative exponential relationships with moisture content. As the vertical stress increased, the degree of reduction in failure resistivity decreased across different moisture contents. Under different moisture contents, the failure resistivity of the specimen generally decreases with increasing vertical pressure.

Keywords: cement-improved soil; electrical resistivity; shear strength; experimental study