饱和珊瑚砂液化特性动三轴试验研究  

Dynamic triaxial tests of the liquefaction characteristics of saturated coral sand

作　　者：郭舒洋 崔杰[1] 吴杨 单毅 中田幸男 梶山慎太郎 GUO Shuyang;CUI Jie;WU Yang;SHAN Yi;Yukio Nakata;Shintaro Kajiyama(School of Civil Engineering,Guangzhou University,Guangzhou 510006,Guangdong,China;School of Civil Engineering,Yamaguchi University,Ube 755-8611,Japan)

机构地区：[1]广州大学土木工程学院,广东广州510006 [2]山口大学地盘工学,日本山口755-8611

出　　处：《地震工程学报》2024年第1期84-94,共11页China Earthquake Engineering Journal

基　　金：国家自然科学基金(51778159)。

摘　　要：为调查饱和珊瑚砂液化相关特性与发展规律,针对饱和Chibishi珊瑚砂,开展一系列不排水循环三轴试验,研究相对密度D r和循环应力比CSR对饱和Chibishi珊瑚砂的超孔隙水压力Δu、轴向应变εa及动强度特性的影响,并分析不同地区珊瑚砂抗液化强度的差异性。结果表明,饱和Chibishi珊瑚砂的Δu发展模式根据不同的CSR水平可以分为前期均匀增长型、前期突增型和后期突增型;此外,采用一种新的孔压模型对前期均匀增长型、前期突增型的孔压比r u进行表征,Chibishi珊瑚砂在相同的D r条件下,双幅应变εDA达到5%的循环次数N随着CSR水平的增加而逐渐减小;各珊瑚砂在同一里氏震级对应的等效循环振动次数下,抗液化强度CRR的增长模式存在显著差异。研究结果可丰富对珊瑚砂液化特征的认知,同时对近岸和沿海工程的抗震设计提供参考依据。For the careful examination of the mechanical behavior of saturated coral sand,a series of undrained cyclic triaxial tests was performed on saturated coral sand(Chibishi).The effects of different relative densities(D r)and cyclic stress ratios(CSRs)on the excess pore water pressure(Δu),axial strainεa,and dynamic strength of coral sand were explored.Three main types of“Δu”,including uniform rising in the early stage,sudden rising in the early stage,and sudden rising in the late stage,can be developed in the presence of various CSRs.In addition,a new pore pressure model was used to characterize the pore pressure ratio r u with uniform growth and sudden increase in the early stage.Under the same D r,the number of cycles gradually decreased with the CSR when the axial strain with double amplitudeεDA=5%was considered.Under equivalent dynamic load,differences in the development of cyclic liquefaction resistance for various coral sands were detected.This study enriches the understanding of the liquefaction characteristics of coral sand and provides a reference for the seismic design of nearshore and coastal projects.

关 键 词：饱和珊瑚砂 孔压发展 轴应变发展 动强度 

分 类 号：P319.56[天文地球—固体地球物理学]