基坑工程内支撑后拆除工艺分析与实践

Analysis and Practice of Demolition After Internal-support Technology in oundation Pit Engineering

简要评述了常规内支撑换撑时的施工情况及存在的问题,讨论了常规内支撑换撑方法的优缺点,并介绍了不拆除内支撑直接进行上部结构施工的具体做法。通过计算传统换撑法与内支撑后拆除法对支护结构的影响,并与实测数据进行对比,论证了内支撑后拆除技术的可行性。主要结论包括:在不拆除内支撑的情况下先进行上部结构施工,同步施工地下室外墙防水后回填基坑肥槽具有可行性;传统拆撑法及内支撑后拆除法对控制支护桩水平位移影响比较接近;内支撑后拆除法产生的桩身弯矩、支撑轴力、周边地面沉降均比传统拆撑法小,可节省建材,降低工程建设费用,减少对周边环境的影响,对工程建设较为有利;内支撑后拆除法施工技术安全可靠,特别适用于工期紧张、采用传统拆撑法可能对周边环境造成较大影响的项目。

This paper briefly reviews the construction situation and existing problems of support replacement of the conventional internal support,discusses the advantages and disadvantages,and introduces the detailed cases of directly constructing the superstructure without removing the internal support.By calculating the influence of the traditional method and demolition method after internal-support on the support structure and compared with the measured data,the feasibility of the demolition method after internal-support technology is demonstrated.The main conclusions include:It is feasible to carry out the construction of the superstructure firstly without removing the internal support,and then backfill the foundation pit fertilizer tank after the waterproofing of the basement wall simultaneously;The influence of the two methods on the displacement control of supporting piles is similar;The pile bending moment,supporting axial force and surrounding ground settlement generated by the demolition method after internal-support are all smaller than the traditional demolition method,which can save building materials,reduce project construction costs,reduce the impact on the surrounding environment,and is more favorable to the project construction;The demolition after internal support technology is safe and reliable,especially suitable for projects,whose construction period is tight and traditional method may have a greater impact on the surrounding environment.