考虑软土应变软化效应的深埋式大圆筒承载性状分析  

Bearing Behavior of Deeply-embedded Large-diameter Cylindrical Structure Considering Strain Softening Effect of Soft Clay

作　　者：吴宜鹏 范庆来[1] 任增乾 陈箫笛 WU Yipeng;FAN Qinglai;REN Zengqian;CHEN Xiaodi(Center for Marine Civil Engineering Technology,Ludong University,Yantai 264025,China;Yantai Muping District Housing and Urban-Rural Construction Bureau,Yantai 264000,China)

机构地区：[1]鲁东大学海洋土木工程技术研究中心,山东烟台264025 [2]烟台市牟平区住房和城乡建设局,山东烟台264000

出　　处：《防灾减灾工程学报》2022年第4期859-865,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：山东省自然科学基金项目(ZR2019MEE010);烟台市科技创新发展计划项目(2021XDHZ071)资助。

摘　　要：深埋式大圆筒结构近年来在我国深水软土地区的港口、跨海通道建设中得到了广泛应用,但是软土强度的应变软化效应对于其承载性状的影响没有得到系统的研究。在基于Tresca屈服准则的理想弹塑性模型中引入软土强度随着塑性应变累积的衰减规律,进而对软土中深埋式大圆筒结构的水平承载力特性进行了比较系统的数值分析。计算结果表明,考虑软土应变软化效应时,大圆筒结构的承载力明显降低,而且地基土强度的灵敏度、相对延性以及加固范围对于大圆筒结构承载力影响较大;软土地基加固前后,大圆筒在水平荷载作用下的失稳破坏模式发生改变,从加固前的双面破坏机制演变为加固后的单面破坏机制。In recent years,the deeply-embedded large-diameter cylindrical structure has been widely used in the construction of ports and cross-sea passages in soft soil under deep water in China. However,the effect of strain softening of soft soil on the bearing capacity of the structure has not been studied systematically. By introducing the attenuation law of soft soil strength with the accumulation of plastic strain into the ideal elastic-plastic model based on the Tresca yield criterion,the lateral capacity of the deeply-embedded cylindrical structure in soft soil was analyzed. The results show that the bearing capacity of the large cylinder structure reduces significantly when the strain softening effect of the soft soil is considered,and the sensitivity,relative ductility and reinforcement range of the soft soil have a great influence on the lateral capacity of the structure. The failure mechanisms of the large cylinder under horizontal loading change from a double-sided failure mode before reinforcement to a single-sided failure mode after reinforcement.

关 键 词：大圆筒结构 软土 承载力 应变软化 失稳破坏机制 

分 类 号：TV222.2[水利工程—水工结构工程]