基于接触面参数反演的格栅式地下连续墙桥梁基础竖向承载特性数值分析  

Numerical analysis for vertically loaded lattice-shaped diaphragm wall based on an approach for determining interfacial parameters

作　　者：吴九江[1,2] 文华[1] 程谦恭[2] 张建磊[2] 李艳[2] 

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]西南交通大学地质工程系,四川成都611756

出　　处：《岩土工程学报》2016年第8期1456-1465,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金重点基金项目(41530639);国家自然科学基金面上基金项目(41172260;41372292);长江学者和教育部创新团队发展计划项目(IRT13092);西南科技大学博士基金项目(15zx7152)

摘　　要：格栅式地下连续墙是一种新型的桥梁基础形式,其竖向承载特性研究在国内外尚处于起步阶段。首先,在接触面参数敏感性分析的基础上,提出了一种接触面参数反演的简化分析方法。然后,基于接触面参数反演方法,利用FLAC3D对日本青森大桥主塔P9基础(六室墙)进行了数值模拟,研究结果表明:数值计算的Q–s曲线与实测曲线基本吻合,从而验证了所提出接触面参数反演方法的正确性;基础的外侧摩阻力沿墙身在深度和宽度方向上表现为空间差异分布,外侧摩阻力在外墙边角位置处的发挥程度最高,且外墙短边的外侧摩阻力发挥程度略高于外墙长边;由于格室数目较多,六室墙内部土芯应力重叠现象严重,即"群墙效应"明显,从而使得内摩阻力的发挥十分有限;在较大荷载下,端部边角位置处会出现较为严重的应力集中现象,在基础设计时应引起重视;在加载过程中,基础的荷载传递特性表现为逐渐由"端承–摩擦墙"向"摩擦–端承墙"转变。As a new type of bridge foundation, the vertical behavior of lattice-shaped diaphragm wall （hereinafter for LSDW） is rarely studiedby now.An approach for determining interfacial parameters is proposed based on the sensitivity analysis. Then, a numerical analysis for the main tower foundation of the Aomori bridge foundation （an LSDW with six chambers） is conducted to investigate the vertical behavior of LSDWs based on the proposed approach for determining interfacial parameters. Itis found that the computedQ-s curve agrees well with the measured data and the proposedapproachcan be then verified essentially. The distribution of theouter skin friction varies along with the wall body from different directions, and the outer skin friction at the corner location is thelargest. The exertion degree of the inner skin friction is limited to a relatively small scaleowing tothatthe chamber number of the foundation is large enough. Stress concentration occurs at the corner part of the wall bottom when the load level is relatively high, which should be noticed during the design phase. During the whole loading process, the foundation changesfrom an end-frictional bearing wall to a frictional-end bearingone.

关 键 词：敏感性分析 接触面参数反演 格栅式地下连续墙 竖向承载特性 

分 类 号：TU43[建筑科学—岩土工程]