欠固结地层静止侧压力简化计算方法  

Simplified calculation method for lateral pressure at rest in the under-consolidation stratum

作　　者：乔亚飞[1,2] 逯兴邦 黄俊[3] 丁文其[1,2] QIAO Ya-fei;LU Xing-bang;HUANG Jun;DING Wen-qi(Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China;China Construction Second Engineering Bureau Ltd.South China Branch,Shenzhen,Guangdong 650021,China)

机构地区：[1]同济大学,土木工程学院,地下建筑与工程系,上海200092 [2]同济大学,岩土及地下工程教育部重点实验室,上海200092 [3]中国建筑第二工程局有限公司华南分公司,广东深圳650021

出　　处：《岩土力学》2020年第11期3722-3729,共8页Rock and Soil Mechanics

基　　金：上海市青年科技英才杨帆计划(No.19YF1451400);横琴口岸及综合交通枢纽开发工程项目基坑设计施工关键技术工程咨询及大规模基坑群理论研究技术服务工程(No.CSCEC2B-SZ-HQKA-ZY-080)。

摘　　要：大量工程实践表明:正确预估欠固结地层的静止侧压力大小对工程的稳定性分析和安全设计十分重要。因此,通过理论分析和数值模拟深入探讨了固结排水过程中地层侧向压力的变化规律,建立了静止侧压力与超固结比OCR的联系,提出了等效静止土压力系数的概念和计算公式,形成了考虑OCR影响的欠固结地层静止侧压力简化计算方法,并用数值模拟和试验结果进行了验证。提出的等效静止土压力系数实现了欠固结地层和正常固结地层侧压力计算的统一。研究结果表明:欠固结地层的静止侧压力随超固结比OCR的增大而线性减小,且随土体有效内摩擦角的增大,OCR对侧向压力的影响越大。上述研究成果可为欠固结地层的土压力计算提供技术支撑。Lots of practical projects have revealed that the accurate calculation of lateral pressure at rest in the under-consolidation stratum plays a crucial role in the stability analysis and safety design.Therefore,this paper investigates the evolution of lateral pressure at rest during consolidation in detail by theoretical analysis and numerical simulation.The relationship between the lateral pressure at rest and the overconsolidation ratio(OCR)is established,and a new method for calculating the lateral pressure at rest in the under-consolidation stratum is proposed.A new concept of equivalent earth pressure coefficient at rest is introduced in consideration of OCR effects.The proposed method is validated by the results of numerical simulation and laboratory tests.Moreover,the proposed equivalent earth pressure coefficient achieves a unified method for calculating the lateral pressure at rest in the both under-consolidation and normal consolidation stratums.The results reveal that the lateral pressure at rest in the under-consolidation stratum decreases linearly with the increase of OCR,and such OCR effect becomes more obvious as the effective friction angle of soil increases.The results of this paper could technically support the calculation of earth pressure in the under-consolidation stratum.

关 键 词：欠固结土 超固结比 静止侧压力 固结过程 水压力 

分 类 号：TU411[建筑科学—岩土工程]