基于扰动状态理论的沈阳砾砂修正邓肯-张模型  

The Modified Duncan-Chang Model for Gravelly Sand in Shenyang Based on the Disturbed State Concept

作　　者：汪智慧[1,2] 陈晨[2,3] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]中国建筑东北设计研究院有限公司,辽宁沈阳110023 [3]东北大学资源与土木工程学院,辽宁沈阳110003

出　　处：《沈阳建筑大学学报（自然科学版）》2017年第1期68-76,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(51578116);中建股份科技研发项目(CSCEC-2014-Z-35)

摘　　要：目的研究沈阳地区砾砂受扰动影响的应力-应变关系,以相对密实度为媒介,推导出考虑扰动影响的修正邓肯-张模型,为实际岩土工程问题的计算提供理论依据.方法针对沈阳地区砾砂进行三轴固结排水剪切试验;并基于扰动状态理论,采用相对密实度Dr为扰动参量,提出能考虑扰动影响的统一扰动度函数,并将其引入Duncan-Chang模型中,结合三轴试验结果,提出适用于沈阳地区砾砂的修正D-C模型;最后将试验曲线与理论计算曲线进行对比分析.结果中密或密实状态砾砂,应力-应变关系呈应变软化型;峰值强度会随围压增大而增大;峰值强度也会随Dr的增大而增大.传统D-C模型中的参数K和峰值强度(σ1-σ3)f受扰动影响程度较大,而参数n和Rf在扰动过程中变化微小.结论采用笔者提出的考虑扰动影响的修正模型计算结果较传统D-C模型更接近于真实的试验结果.因此,该修正模型可更好地模拟沈阳地区粗颗粒土的强度与变形特性.In this paper, the strength-strain relations of the gravelly sand in Shenyang considering the influence of disturbance are established by the triaxial consolidation drained shear tests and the modified Duncan-Chang model focused on gravelly sand in Shenyang is obtained which can provide the theory basis for practical geotechnical engineering. Based on the theory of DSC, the general disturbance function which can consider the influence of disturbance is established in which Dr is used as a parameter of disturbance. Combined the results of triaxial tests, the modified DuncanChang model focused on gravelly sand in Shenyang is obtained in which the disturbance function is introduced. The test results show that the stress-strain relationship curve tends to soften for the medium dense and the gravelly sand and the disturbance has big influence of the parameter K and the peak strength（ σ1 -σ3 ）f in traditional D-C model and it has little influence of the parameter n and the failure ratio Rf. Also, the calculation curves by the modified model are analyzed comparing the test curves and the results show that it is better to use the modified model considering the influence of disturbance comparing the traditional models as the former can make a better description of the strength and the deformation characteristics of the coarse-grained sand in Shenyang area.

关 键 词：沈阳地区 砾砂 三轴试验 相对密实度 扰动函数 修正邓肯-张模型 

分 类 号：TU411.4[建筑科学—岩土工程]