随着城市化进程中对老城区的综合改造,出现越来越多复杂环境条件下的深基坑工程。单一支护形式在处理复杂环境下的深基坑工程很难同时满足使用要求和经济效益,复合支护形式成为解决这一难题的有效手段。针对郑州地区基坑工程中遇到的既有电力隧道、防空洞以及旧桩基复杂环境下,通过对工程所处地理环境、工程地质条件、基坑工程施工条件、周边建筑安全等方面的综合分析,采用桩锚/土钉复合支护结构方案进行处理。工程监测结果表明所采用方案能较好地解决基坑工程遇到既有电力隧道、防空洞以及旧桩基时的复杂环境条件下基坑支护的问题。
An increasing number of deep foundation pit project in complex conditions has emerged with the comprehensive transformation of old urban area in the process of urbanization. Deep foundation pit projects with single sup-port could not easily meet the requirements of usage and economic benefit simultaneously, which, however, can be effectively addressed by composite support. In this research, a foundation pit project encountering existing power tunnel, air-raid shelter and old pile foundation in Zhengzhou city was taken as a case study of composite support form. Through analysis on geographical environment, engineering geological conditions, construction condition, and construction safety, a composite support plan integrating pile anchor and soil nailing structure is adopted. Monitoring results show that the composite support plan could well solve the problems posed by complex environment.
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