软土地基格栅式地下连续墙与群桩桥梁基础竖向承载性状对比模型试验研究

发布时间：2018-06-24 07:15

本文选题：格栅式地下连续墙 + 群桩　；参考：《岩土工程学报》2014年09期

【摘要】：在软基上修建高速铁路,其桥梁墩台须采取必要的加固措施,以满足轨道线路对沉降的严格要求,而新型桥梁基础——格栅式地下连续墙(以下简称:格栅式地连墙)为解决这一问题提供了新的技术方案。为分析软土地基高铁格栅式地连墙桥梁基础的承载性状,对采用相近材料用量的3种基础形式(群桩与单室、两室格栅式地连墙)进行了两组对比模型试验,结果表明:相同荷载下,单室与两室格栅式地连墙的沉降量相近,群桩基础的沉降量较大,单室与两室的极限承载力分别为群桩的116.7%与120.4%;群桩侧摩阻力呈"L"形分布,格栅式地连墙外摩阻力呈不对称"M"形分布,其土芯侧摩阻力的发挥主要集中在墙体端部以上约占墙体深度1/4的部位;3种基础形式的承台土反力及侧摩阻力的荷载分担百分比均较小,基础承载特性均表现为摩擦端承墙(桩);相同荷载下,群桩的单位端阻力大于格栅式地连墙基础,而相同单位端阻力下,群桩的沉降量亦大于格栅式地连墙基础;在软土地基,当不能利用土体共同承担上部荷载时,采用地下连续墙基础替代群桩将会起到提高基础承载力,减少沉降量等的作用。
[Abstract]:For the construction of high-speed railway on soft foundation, the bridge pier and abutment must take necessary reinforcement measures to meet the strict requirements of the track line for settlement. The new bridge foundation-grille diaphragm wall (hereinafter referred to as grille ground connection wall) provides a new technical scheme to solve this problem. In order to analyze the bearing behavior of high speed grille bridge foundation on soft soil foundation, two groups of comparative model tests were carried out on three kinds of foundation forms (pile group and single chamber, two-compartment grille type ground connection wall) with similar material content. The results show that under the same load, the settlement of single and two-compartment grille type ground connecting walls is similar, the settlement of pile group foundation is larger, the ultimate bearing capacity of single chamber and two rooms is 116.7% and 120.4 of pile group respectively, and the frictional resistance of pile group is "L" shape distribution. The frictional resistance outside the wall is distributed in an asymmetric "M" shape. The exertion of soil core side friction is mainly focused on the proportion of soil reaction force and lateral friction load sharing in three kinds of foundation forms, which are about 1 / 4 of the wall depth above the end of the wall. Under the same load, the unit end resistance of pile group is greater than that of grille type ground connecting wall foundation, and the settlement of group pile is larger than that of grid type ground connecting wall foundation under the same unit end resistance, and the settlement of group pile is larger than that of grid type ground connecting wall foundation under the same load. When the soil can not be used to bear the upper load together, the use of underground continuous wall foundation instead of pile groups will improve the bearing capacity of the foundation and reduce the amount of settlement.
【作者单位】：西南交通大学地质工程系;西南科技大学土木工程与建筑学院;
【基金】：国家自然科学基金项目(41172260,41372292,51108393) 高等学校博士学科点专项科研基金项目(20110184110018) 教育部创新团队项目(IRT13092) 四川省科技支撑计划项目(2013GZ0071) 西南交通大学2014年博士研究生创新基金项目
【分类号】：U443.1

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