土工格室加筋正常固结粉质黏土应力应变响应  

Stress-strain response of geocell-reinforced normally consolidated silty clay

作　　者：宋飞[1] 石磊 樊明尊 SONG Fei;SHI Lei;FAN Mingzun(School of Highway Engineering,Chang′an University,Xi′an 710064,China)

机构地区：[1]长安大学公路学院,西安710064

出　　处：《地质科技通报》2024年第1期184-193,共10页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(52278328);中建新疆建工科技研发课题(65000022859700210197)。

摘　　要：土工格室加筋正常固结粉质黏土对工程建设意义重大。基于土工格室与填土的相互作用机制和增量法,采用弹塑性理论、邓肯-张双曲线模型、修正剑桥屈服函数以及剪胀方程,推导了土工格室加筋正常固结黏土的应力应变响应计算模型,进行了土工格室加筋正常固结黏土的三轴固结排水剪切试验,实测不同围压下的应力应变关系,采用三轴试验结果验证了所提理论模型的正确性和可靠性。此外,采用所提理论模型进行了参数敏感分析,研究了填土的力学性质参数、格室的网格尺寸和力学性质参数对于加筋土应力应变响应的影响。研究结论表明,与砂砾料相似,土工格室约束作用对于正常固结黏土的内摩擦角影响较小,而黏聚力有所增加;随着轴向应变的增加或围压的减小,加筋效果逐渐明显;加筋正常固结黏土的强度和刚度随着非线性弹性常数k的增加、强度参数φ的增加和Rf的减小而增大,常数n对于加筋土应力应变响应影响较小。本研究成果可为工程建设提供理论借鉴。[Objective]The mechanical behavior of normally consolidated silty clay reinforced with geocell is of significance for engineering construction.[Methods]An analytical method was formulated for the prediction of stress-strain responses in geocell-reinforced normally consolidated clay in this paper.In addition,a series of conventional triaxial compression tests were conducted on geocell-reinforced normally consolidated clay to investigate the reinforcement effects and validate the effectiveness of the proposed method.The predicted stress-strain responses are in good agreement with those measured in the tests,affirming the efficacy of the proposed method.In addition,parametric studies were conducted to investigate the effects of the mechanical properties of the backfill pocket size and the stiffness of the geocell on the stress-strain response of the geocell-reinforced clay.[Results]The study results show that the geocell-reinforced normally consolidated clay exhibits strain hardening.The internal friction angle of the reinforced clay remained similar to unreinforced clay,whereas apparent cohesion increased due to geocell confinement.Furthermore,the reinforcement effect on the clay intensified with increasing axial strain and reducing confining pressure.The strength and stiffness of the reinforced clay increase with the increase in the nonlinear elastic parameter k and the reduction in R f.[Conclusion]The results will be guidance for engineering construction.

关 键 词：土工格室 加筋正常固结粉质黏土 应力应变响应 三轴压缩试验 参数敏感分析 轴向应变 

分 类 号：P642.16[天文地球—工程地质学]