摘要:
上海市区某13层建筑,无地下室,上部结构为短肢剪力墙体系,基础采用墙下预制混凝土管桩。该项目正式投入使用前在其背后大量堆土,导致建筑产生了较大的整体水平变形。为消除安全隐患,采用锚杆静压桩进行地基加固。加固钢管桩的桩长、单桩承载力、桩数都与原有桩基相同。在原基础梁之间的房间区格内设置700 mm厚筏板,新增的钢管桩布置于筏板下,通过筏板实现对上部结构的支承作用,筏板也同时作为静压桩施工的反力结构。为确保荷载传递的可靠性,提出了钢管桩与筏板,以及筏板与原基础梁之间的连接做法。另外,由于结构底层净空受限,通过改造,使得压桩设备可在低于2.5 m左右净空条件下完成钢管桩的压入施工。目前该建筑最大沉降10 mm左右,表明地基加固的作用是有效的。
Abstract:
For the a building with 13 floors high and no basemnt located in Shanghai, short leg shear wall system is used for the superstructure, and the foundation beams with precast tubular piles are used to be the foundation type. Before service of the project, may soils are pulled behind the building, and large deformation of the building is induced. For safety consideration, anchor-jacked piles are used to be as the foundation reinforcement. The steel pipe piles are used, which are the same as the existing ones. The total number is 116. In order to strengthen the rigidity of the original foundation and to make it easier for pile layout and load transfer, the raft with thickness of 700 mm is hoped to connect the existing foundation beams and the new piles. The steel pipe piles are located under the raft, and the raft will be the counterforce structure for the anchor-jacked pile. The connection node between piles and raft and that between raft and the existing foundation beams are proposed herein. The equipment is reformed to realize the construction of anchor-jacked piles under the clearance less than 2.5 m. So far, the maxium settlement of the building is about 10 mm, which shows the effect of the reinforcement by the anchor-jacked piles is remarkable.
下载:
