【摘要】 被动区加固是控制基坑变形的有效措施,为深入研究基坑被动区软土加固范围对基坑变形的影响,以澳门填海区某建筑深基坑工程为分析实例。根据室内土工试验结果,获取各土层物理力学参数,通过改变加固深度及范围等影响基坑变形的主要因素,建立三维有限元数值模型并进行精细化模拟。研究结果表明:三维有限元模型可以较好地分析围护结构的变形规律,模拟结果与实测值较为一致;未采取被动区加固时,基坑变形无法满足要求;被动区旋喷桩加固能够显著降低围护结构横向位移和坑底隆起变形,但存在最优加固范围;当加固宽度与深度为6～8m时,控制基坑变形效果最理想,超过此范围后,基坑变形降低幅度有限。满堂加固可以有效控制基坑隆起变形,但施工成本较高。更多还原

【Abstract】 The reinforcement of passive area is an effective measure to control the deformation of foundation pit. In order to deeply study the influence of reinforcement extent on pile displacement in the passive zone of foundation pit, a practical excavation project located at reclamation of Macao is selected as the target. On the basis of laboratory test data, the physical and mechanical parameters of soils are obtained. And we establish a 3 D numerical model in which factors affecting the pile displacement such as the reinforcement shape and size are taken into consideration. The testingresults show that the simulation could well reflect the actual deformation of pile support system. The deformation of foundation pit cannot meet the requirements without passive area reinforcement. The reinforcement in the passive zone can significantlydecreasedeformation of the foundation pit. And an optimum reinforcement extent is existing, namely the reinforcement width and depth are approximately equal of 6～8 m. Once the reinforcement extent exceeds the optimum value, the decrement of foundation pit deformation is negligible. The reinforcement of entire basal soil can effectively control the uplift deformation of foundation pit, and the construction cost is higher.更多还原