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冰川冻土 ›› 2000, Vol. 22 ›› Issue (3): 278-281.

• 研究论文 • 上一篇    下一篇

繁华市区含水地层水平冻结及暗挖法施工

汪崇鲜, 楼根达, 马玉峰   

  1. 煤炭科学研究总院北京建井研究所, 北京100013
  • 收稿日期:1999-07-16 修回日期:2000-04-05 出版日期:2000-08-25 发布日期:2012-04-26

The Technique of Horizontal Freezing and Underground Excavating Within Water Bearing Soft Soil in Busy Sections of a City

WANG Chong-xian, LOU Gen-da, MA Yu-feng   

  1. Central Coal Research Institute, Beijing 100013, China
  • Received:1999-07-16 Revised:2000-04-05 Online:2000-08-25 Published:2012-04-26

摘要: 结合上海繁华市区内地铁建设工程实践,介绍了含水软粘土地层中水平冻结加固和暗挖法施工技术.在借鉴传统地层冻结法的基础上,应用新近开发的冻结孔孔口密封装置、组合钻头以及"跟管"钻进技术,解决了含水软粘土地层中水平冻结管铺设的关键技术;采用特制的低温伸缩接头,解决了超长距离盐水干管在盐水降温过程中的冷缩问题;应用"新奥法"原理,通过设置土体冻胀卸压孔、冻土融沉注浆技术、合理的支护技术等综合技术措施,将地表沉降和地铁隧道最终位移控制在10mm以内.该技术在我国上海繁华市区内首次应用成功,为我国城市建设中繁华市区的地下工程建设提供了新的途径.

关键词: 地铁旁通道, 软土地基, 水平地层冻结, 暗挖法

Abstract: In the light of the project of Shanghai Subway Line 2 in busy sections. this article describes a horizontal freezing technique for ground reinforcing and a method of underground excavating within water bearing soft soil. Under the basis of the traditional ground-freezing method, a new combined technique of sealed-device on the orifice of freezing-hole, assembled-aiguille and "following-pipe" infixing is employed to lay horizontal freezing-pipes in water bearing soft clay, as a key-technique. A special low temperature flexing tie-in is used to solve the coldly-shri nking matter of over-long saltwater tube in the process of lowering saltwater temperature. The principle of" New Austria Method" is applied to underground excavation. And a series of technological measures, such as setting discharging-pressure bore on frozen-expanding soft-clay, melted-settling grouting technique of frozen clay, and rationally reinforcing technique, are used to control the settlement of the ground surface within the range of 10 mm and the ulti-mate displacement of metro tunnel. Freezing boreholes are arranged in all directions, and the space between the boreholes is less than 0.6 m. The cross-section is a rectangle with a frozen wall of 1.2 m in thick and a mean temperature of -8.0℃. The colding liquors is saltwater in the temperature of -24~-26℃ and the freezing time is 40 d for active frozen period and 35 d for maintenance period. After a horizontal freezing processing, the underground excavation begin. A successful example is the Shanghai Subway Line 2 constructed in busy sections. Thus a new way for construction within water bearing soft soil under busy sections of a city in China is put forward.

Key words: thoroughfare of subway, soft soil ground, horizontal freezing, underground excavating

中图分类号: 

  • U455.49