以济南地铁R3线龙洞庄车站基坑工程为研究背景，利用FLAC3D对紧邻高层建筑结构下基坑多种支护方案进行仿真模拟，分析各方案下基坑稳定性及支护桩变形规律，综合考虑支护方案的安全性、经济性、工期及可行性等因素建立多属性决策模型，并甄选出最优支护方案。结果表明： 针对基坑安全性来说，原支护方案下，超载侧支护桩向基坑内部整体位移过大，超出了安全允许值； 采用双排桩的改进方案，超载侧支护桩水平位移值有所降低，但受制于场地条件，施工难度增加； 采用桩锚支护的改进方案，两侧支护桩水平位移均在安全允许范围之内，超载侧支护桩变形可控； 采用桩撑支护的改进方案，偏压荷载侧支护桩水平位移值较小，但工程造价较高； 利用多属性决策模型将各方案目标值的优基数进行加权求和计算，判定桩锚支护形式为最优方案。

The supporting schemes of deep foundation pit of Longdongzhuang Station on Line R3 of Jinan Metro closely adjacent to a highrise building are numerically simulated; and then the foundation pit stability and supporting piles deformation under different supporting schemes are analyzed. Finally, a multiple attribute decisionmaking model is established and the optimum supporting scheme is selected considering safety, economy, construction schedule and feasibility of every supporting scheme. The results indicate that: 1) In view of safety, the lateral displacement of supporting pile towards internal foundation pit is too large to keep safe under original supporting scheme. 2) The horizontal displacement of supporting pile decreases; but the construction difficulty increases under doublerow piles supporting scheme. 3) The horizontal displacement of pile closed to highrise structure is allowable and the deformation of supporting pile close to highrise building can be controlled under pile+anchor bolt supporting scheme. 4) The horizontal displacement of supporting pile close to highrise building is very small; but the construction cost is much higher under improved pile+shaped steel supporting scheme. 5) By establishing and using the multiple attribute decisionmaking model, the optimum supporting scheme of pile + anchor bolt is decided.