考虑水合物填充和胶结效应的深海能源土弹塑性本构模型  

An elastoplastic model for energy soils considering filling and bonding effects

作　　者：袁庆盟 孔亮[1,2] 赵亚鹏 YUAN Qing-meng;KONG Liang;ZHAO Ya-peng(School of Civil Engineering,Qingdao University of Technology,Qingdao,Shandong 266033,China;School of Science,Qingdao University of Technology,Qingdao,Shandong 266033,China)

机构地区：[1]青岛理工大学土木学院,山东青岛266033 [2]青岛理工大学理学院,山东青岛266033

出　　处：《岩土力学》2020年第7期2304-2312,2341,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.11572165,No.51778311)。

摘　　要：水合物的填充效应和胶结效应增大了能源土的密实性和强度,使能源土呈现出类似于密实砂土或胶结土的性质。在黏土和砂土的统一硬化模型(CSUH模型)框架下,总结了能源土的力学性质,引入压硬性参量描述水合物对能源土填充和胶结双重作用下的等向压缩特性,引入黏聚强度修正屈服函数并构建了黏聚强度的演变规律,利用状态参数调整剪胀方程,反映能源土剪胀、软化等特性对密实度的依赖性,从而建立能够描述能源土强度、刚度、剪胀与软化等特性的弹塑性本构模型。编制了模型的测试程序,把模拟结果与能源土室内试验结果进行对比。结果表明:提出的弹塑性本构模型能够较好地描述能源土的应力-应变关系、剪缩硬化和剪胀软化等力学特性。The filling and bonding effects of hydrate increase the compactness and strength for gas hydrate-bearing sediments(GHBS),which makes the GHBS exhibiting properties similar to dense sand or cemented soil.Under the frame of unified hardening model of clay and sand(CSUH model),the mechanical properties of GHBS are summarized firstly,and a compressive hardening parameter is introduced to describe the isotropic compression characteristics of GHBS under the double influences of filling and bonding of hydrate.A bonding parameter is put forward to modify the yield function,and an evolution rule of bonding effect is also proposed.The state parameters are used to adjust the dilatancy equation to reflect the dilatancy and softening depending on density.Thus,an elastoplastic model is developed,which can describe the strength,stiffness,shear dilation and strain-softening of GHBS.The model coded and tested,and the simulation results are compared with the experimental ones of GHBS.The results show that the proposed model can well describe the stress-strain relationship,shear contraction with hardening and shear dilation with softening for GHBS.

关 键 词：天然气水合物沉积土 压硬性 黏聚强度 剪胀性 CSUH模型 

分 类 号：TU411[建筑科学—岩土工程]