吉林中部供水工程关键技术问题综述

吉林中部供水工程输水干线线路全长263.45 km,其中隧洞长133.98 km,管线PCCP(钢管、现浇涵)长129.47 km。针对该工程中的关键技术问题:分水枢纽类型、超长有压隧洞技术、TBM选型、隧洞穿越灰岩地区技术、水下岩塞爆破技术、隧洞预应力衬砌技术、直径5.1 m预应力涵技术等,结合中部供水工程的实际情况,从工程实例、技术可行性等方面进行了阐述。分水枢纽选择了调压井类型;总干线有压隧洞长为97.62 km;现浇预应力涵长为2.26 km;采用直线穿灰岩线路隧洞;选择开敞式TBM施工;根据隧洞覆盖层的特点,对15段衬砌应按抗裂设计考虑,采用预应力衬砌,衬砌段总长为14.756 km。工程规模巨大,特别是总干线超长有压隧洞为国内首例,又穿越灰岩地区,这在东北地区尚无先例,其勘察、试验、科学研究和专题研究还有待深入开展,为工程的决策提供重要技术支撑。

Summary of Key Technical Issues of the Water Supply Project from Songhua River to the Central Cities of Jilin Province

The main line of water supply project from Songhua River to the central cities of Jilin province has a total length of 263.45 km,including 133.98 km of tunnel and 129.47 km of Prestressed Concrete Cylinder Pipe(steel pipe and cast-in-situ culvert).Key technical issues of this project are summarized as follows: type of water diversion project,technology of the ultra-long pressure tunnel,selection of TBM(Tunnel Boring Machine),technology of the tunnel across limestone area,technology of underwater rock plug blasting,technology of prestressed reinforced concrete lining,and technology of the prestressed circular culvert(D=5.1 m).The practical situation of the project and the technical feasibility are elaborated.The water diversion project is selected as surge-tank type;the pressure tunnel has a length of 97.62 km,and cast-in-situ culvert 2.26 km;the tunnel crosses the limestone area in a straight line;and open TBM construction is adopted.In the light of the characteristics of tunnel’s overburden layer,15 segments of the lining should be designed to resist cracks,and hence prestressed lining is adopted with a total length of 14.756 km.The project is the first in northeast China to cross limestone area with ultra-long pressure tunnel.The investigation and researches will provide technical support for the project.