临江漫滩区超深地连墙成槽变形影响因素分析

Analysis of Factors Affecting the Deformation of Ultra Deep Diaphragm Walls in the Floodplain Area of Linjiang River

为研究深厚砂层地连墙槽壁稳定性特征及其主要影响因素,以南京地铁11号线柳洲东路站地连墙成槽施工为工程依托,通过数值模拟方法建立有限元模型。研究结果表明:地表沉降和槽壁水平位移的发展主要集中在成槽前期,而成槽后期变化较小。成槽结束时地表最大沉降为21.8 mm,产生位置距槽壁距离约3.6 m处,沉降影响范围约为距槽壁10 m范围内。槽壁水平最大位移发生在地面以下4.4 m粉质黏土层中。槽壁加固对于控制浅层土体成槽失稳具有显著效果,地下水位埋深对地表沉降的影响最大,浆面深度、泥浆重度、槽段长度次之,软土层厚度影响最小。浆面深度对槽壁水平位移的影响最大,地下水位埋深、槽段长度、泥浆重度次之,软土层厚度影响最小。

In order to study the stability characteristics of diaphragm wall trench wall in deep sand layer and its main influencing factors,the finite element model was established by numerical simulation method based on the construction of diaphragm wall trench in Liuzhoudonglu station of Nanjing Metro Line 11.The research results indicate that the development of surface settlement and horizontal displacement of the trench wall is mainly concentrated in the early stage of trench formation,while the changes in the later stage of trench formation are relatively small.At the end of the trench formation,the maximum surface settlement is 21.8 mm,occurring at a distance of approximately 3.6 m from the trench wall,and the impact range of the settlement is approximately 10 m from the trench wall.The maximum horizontal displacement of the groove wall occurs in the silty clay layer 4.4 m below the ground level.The reinforcement of the trench wall has a significant effect on controlling the instability of shallow soil during trench formation.The buried depth of the groundwater level has the greatest impact on surface settlement,followed by the depth of the slurry surface,the weight of the slurry,and the length of the trench section.The thickness of the soft soil layer has the smallest impact.The depth of the slurry surface has the greatest impact on the horizontal displacement of the trench wall,followed by the burial depth of the groundwater level,the length of the trench section,and the weight of the slurry,while the thickness of the soft soil layer has the smallest impact.