摘要拟建苏州市赛得科技金螳螂工程运营中心位于苏州市工业园区金田路东，新发路底，星华街西侧。本基坑西北角距离已建成围墙8.2m，距离星华街一侧埋设有市政管线，其余周边大部分区段环境条件比较宽松。该工程由双塔式主楼、整体裙房及两层地下车库组成，主楼及裙房下设2层地下室。基坑占地面积约12000m2，周长约为440m。拟建场地位于长江三角洲南缘，属三角洲冲、湖积平原地貌。场地大部分地段原为水塘，现经人工填平，地势较平坦。±0.00相当于85国家高程基准3.20m，基坑开挖深度约为9.30m。52541

本着安全可靠、经济合理、技术可行、施工方便原则，根据基坑周边环境特点，为确保安全，以“变形”控制设计。本工程采用了浅层卸土放坡结合深层排桩式支护的梯次组合支护体系，即在基坑周边浅层采用一级放坡开挖，深层采用钻孔灌注桩结合水平支撑体系。浅层卸土放坡可减小排桩支护深度和钻孔灌注桩的侧向水土荷载，实现一道支撑开挖，可减小围护桩直径节省工程造价。为有效降低地下水位，基坑上部周边浅部填土层用压密注浆封闭止水；基坑中下部及深部用深层搅拌桩封闭落底式帷幕止水，同时配合坑内管井及集水沟进行降排水。在基坑施工过程中放坡坡顶严格限制堆土或堆载，防止坡体产生较大变形。

本设计包括支护体系选型、围护结构的强度计算、变形计算、土体稳定性计算、渗透计算、降水计算、电算校核、施工组织设计等内容。

毕业论文关键词：深基坑；钻孔灌注桩；内支撑；深层搅拌桩；稳定验算

Abstract

The proposed Teesside Technology Suzhou Gold Mantis engineering operations center is located in Suzhou Industrial Park Jin Tian Road East, end of the Xinfa road, Xinghua Street West. The  distance between the northwest of foundation pit and the wall is 8.2m, the municipal pipelines have been buried beside the Xinghua Street, most of the remaining section of the surrounding environmental conditions is more lenient. The project consists of twin towers’ building, the overall composition of the podium and two levels of underground garage. Two basements are below the storeys of main buildings and podium. Foundation pit covers about 12000m2.Its circumference is approximately 440m. The proposed site is located in the southern margin of the Yangtze River Delta, is a delta flood plain landscape. Most of the original site is the pond area, which is filled artificially, and the ground is almost level.

With the principle of safety, reliability, reasonable economic, feasible technology, convenient construction, according to the environmental characteristics around the foundation pit, in order to ensure safety, using "distortion" control design. This project uses the echelon support system with shallow dump grading combined with the deep pile supporting , namely superficial layer takes one-level slope excavation around the foundation pit, deep layer takes the horizontal brace system with the nondisplacement pile. Shallow dump grading can be directly reduced  the depth of the pile supporting and lateral soil loads of the nondisplacement pile to achieve a supporting excavation, it can reduce the fender piles’ diameter to save the project cost. To effectively lower the water table, the upper peripheral shallow pit filled with soil compaction grouting closed sealing; deep pit in the lower and closed with deep mixing piles curtain sealing off the hearth, in conjunction with tubewell pit and gullies carried down the drainage. The crest gading severely restricted bulldozers and heap load to prevent a greater slope deformation during the construction process in the pit.

The design includes support system selection, the strength envelope calculation, deformation calculation, soil stability calculation, penetration calculations, precipitation computing, electronic data verification, construction design and so on. 苏州市金螳螂工程基坑开挖支护设计方案+CAD图纸:http://www.751com.cn/gongcheng/lunwen_56459.html