盘道岭隧洞除险加固工程糙率原型观测及过流能力分析  

Prototype Observation of Roughness and Overflow Capacity in Pandaoling Tunnel

作　　者：胡普年 HU Pu-nian(Management Bureau of Water Division Project from Datong River to Qinwangchuan Basin in Gansu Province, Lanzhou 730000, China)

机构地区：[1]甘肃省引大入秦工程管理局,兰州730000

出　　处：《长江科学院院报》2019年第4期67-70,76,共5页Journal of Changjiang River Scientific Research Institute

基　　金：国家重点研发计划项目(2016YFC0401909)

摘　　要：盘道岭隧洞为长距离无压隧洞(长15.723 km),因地层岩性复杂、地质条件恶劣,出现了裂缝、表面混凝土剥蚀、地下水外渗等安全隐患。于2013年9月实施了除险加固,在洞壁套衬了最小衬砌厚度为0.25 m的钢筋混凝土,减小了隧洞过水断面。加固后隧洞表面较原隧洞光滑,糙率有所减小。隧洞过流能力能否满足设计要求,糙率是关键,常规计算及试验难以满足精度要求,为此进行了原型观测。介绍了糙率原型观测的理论依据、观测手段及方法,并对各段观测糙率的合理性及泄流能力进行了分析。观测分析表明:疙瘩沟矩形明渠段、隧洞进口未加固段、隧洞进口加固段和隧洞出口加固段的糙率分别为0.013 07,0.015 49,0.011 16,0.010 52,结合观测断面内的水位测定值,分析得出盘道岭隧洞经除险加固后过流能力满足设计要求。观测成果可为类似引调水工程优化设计、节约工程投资提供科学依据。Hidden dangers such as cracks, surface concrete denudation and groundwater infiltration appeared on Pandaoling tunnel, a long-distance pressure-free tunnel with a length of 15.723 km due to the complex lithology and severe geological conditions. In September 2013, the tunnel was reinforced with lining of a minimum thickness of 0.25 m which reduced the tunnel's overflow section. The reinforcement also reduced the roughness of tunnel surface which is a key factor determining whether the overflow capacity meets design requirement. Conventional calculation and test of roughness could hardly meet accuracy requirements. In view of this, prototype observation was conducted. The theoretical basis, observation approaches and methods of prototype observation are introduced in this paper, and the rationality of observed roughness and discharge capacity of tunnel sections are analyzed. The roughness of rectangular open section, tunnel entrance without reinforcement, tunnel entrance with reinforcement, and tunnel outlet with reinforcement is 0.013 07, 0.015 49, 0.011 16, 0.010 52, respectively. According to the measured water level in the observation section, the overflow capacity of the Pandaoling tunnel after reinforcement meets design requirements.

关 键 词：盘道岭隧洞 糙率 原型观测 过流能力 除险加固 

分 类 号：TV6[水利工程—水利水电工程]