富水砂卵层基坑封闭降水与回灌工程关键技术

根据济南泉域富水砂卵石地层特点,通过文献调查、理论分析、现场实测,并借助数值模拟计算,分析并优化基坑下卧弱隔水层注浆加固方案,得到注浆加固质量控制技术要点,提出端头井土体加固与封闭止水帷幕下辅助降水的关键技术,研发基坑降水回灌一体化系统及配套装备,攻克传统回灌技术存在的抽灌分离、回灌效率低、运维成本高等施工难题,阐述回灌水质处理、自动加压回灌及水位联动回灌等关键技术创新点,改良回灌井过滤器设置及止水段施工技术,形成富水砂卵层基坑封闭降水与回灌工程关键技术,对推广基坑降水与回灌工程的绿色化、信息化、智能化有一定指导作用。

Application of Key Technology to Closed Dewatering and Reinjectionof Foundation Pit of Water Rich Sand Layer

Based on the characteristics of a water-rich sandy pebble stratum in the Jinan spring area, the grouting reinforcement scheme for the weak aquiclude of a basement was analyzed and optimized through literature review, theoretical analysis, field measurement, and numerical simulation. The key technical points of the quality control of grouting reinforcement were obtained, and primary soil reinforcement technologies for the end well and auxiliary dewatering under a closed water stop curtain were proposed. The integrated system of foundation pit dewatering and reinjection as well as the supporting equipment were developed and investigated. The construction problems encountered in traditional reinjection technology, such as pumping and grouting separation, low reinjection efficiency, and high operational and maintenance costs, were resolved. Moreover, the main technological innovation points of reinjection water quality treatment, automatic pressure reinjection, and water level linkage reinjection were presented. Then, the major technologies of reinjection well filter setting and water stop section construction were expounded. The foremost construction technology of the filter setting and water stop section of the reinjection well were improved. This paper is anticipated to serve as a guide in promoting green information and intelligence on foundation pit dewatering and reinjection engineering.