随着我国城镇化建设速度的加快，地下工程特别是基坑工程逐渐成为城市建设中最重要和常见的工作之一，然而城市中建筑密集环境复杂，想要做到科学经济地完成基坑工程，达到预期效果就会比较困难，在如何更加合理地解决基坑问题上还有很大的进步空间。如何更加合理地做好基坑工程，将安全和经济效益最大化，首先就要从本质上认清基坑工程，在实践中积累经验，发现其内部规律。 本文以鹏龙国际大厦基坑为研究背景，在分析其工程地质条件的基础上，进行理论计算及支护结构设计，分析其稳定性。在初步确定支护方案合理可行的前提下，运用FLAC3D软件对该基坑开挖支护过程中的应力应变情况进行模拟，并得出了开挖和支护过程中土体应力、位移变化以及支护结构轴力、变形结果，基坑最大沉降约5.2mm，基坑底最大隆起约22mm，土体最大位移约15mm，支护桩最大水平位移约8.2mm，均满足规范要求，说明该支护形式下基坑是安全稳定的。在此基础上，分析模拟结果，并总结出该基坑在桩与土钉墙联合支护形式下的应力应变的变化趋势，以及分布规律。最后通过对监测数据的分析，将观测数据及其规律与模拟数据及其规律进行对比，得出两者在总体上是一致的，并分析两者差异的产生原因，得出客观规律。 本文以鹏龙国际大厦基坑为例，希望对类似的周边环境较为复杂的，特别是桩和土钉墙联合支护形式的基坑研究，起到抛砖迎玉的作用，为以后的基坑工程研究积累一些实践经验，供读者参考。

Along with the acceleration of urbanization construction speed in our country, underground engineering especially foundation pit engineering has become one of the most important urban development and common work, however, the city buildings densely populated and environment is complex, it will be more difficult to make a scientific and economical completion of excavation to achieve the desired effect. There is much more room for progress on how to solve the problem of foundation pit is more reasonable. How to make a foundation pit engineering more reasonable, and maximize the safety and economic benefits. First we should understand the nature of the foundation pit engineering, accumulate experience in practice and found the internal law. The artical design the support structure on the basis of its analysis of engineering geological conditions, based on Penglong international building foundation pit as the research background, analyze its stability. Under the premise that the scheme is feasible, using the FLAC3D software to simulate the changes of stress and strain in the process of the foundation pit excavation and supporting. Come to the conclusion of stress, displacement, axial force and deformation of the supporting structure. The foundation pit largest settlement is about 5.2mm, the pit maximum uplift is about 22mm, the largest displacement of soil is about 15mm, supporting piles maximum horizontal displacement is about 8.2mm, all of these meet regulatory requirements, shows the foundation pit is safe and stable under the support in the form. On this basis, analyze the results of simulation and concluded the trend of stress and strain in the pit under the form of pile and soil nailing combined support. Finally, analyze the monitoring deta, and the observation deta were compared with simulated deta. Found the two is consistent with the overall, and analyze the causes of the difference between the two deta, obtained the objective laws. Based on the Penglong international building foundation pit as an example, I hope the article can be a reference for the similar engineering, especially the study of piles and soil nailing pit wall combined support form, and accumulated some practical experience for foundation pit engineering research in the future.