国内地铁首条越江区间联络通道结构设计

The Structural Design of Contact Channel of the First Domestic Metro Cross-river Interval

研究目的:武汉地铁2号线越江区间联络通道,是国内地铁首次在长江底砂层中实施的联络通道,其中带有泵房的3#联络通道最大水头高度约56 m,高水压和高风险,结构设计尚无先例可以借鉴和参考,需采用合理的设计方案,以保证结构安全和施工安全。研究结论:本文对位于江底埋深最大的3#联络通道及泵房,进行研究分析,有如下主要结论:(1)实践证明江底砂层采用冻结法加固地层,是安全可靠的,但应尽量优化泵房有效容积,减小集水池体量,降低冻结施工风险;(2)常规的矩形断面集水池设计,难以同时满足冻结施工和结构高水压抗剪双重要求;(3)联络通道采用结构墙体变厚度,集水池水平向采用近椭圆形断面设计方案,取得意想不到的结果,不仅克服高水压抗剪的问题,而且新的结构型式大大改善结构受力,提高结构安全富裕度;(4)该种联络通道结构型式可为其它类似隧道的设计提供借鉴。

Research purposes： The contact channel of Wuhan Metro Line 2, is the first built in the sand layer under Yangtze River of domestic metro. With Pump room of 3# contact channel bears the load of elevating head about 56 m, so it has the characteristics of heavy loads and construction of high risk. There is no precedent for reference, and a reasonable structural design solution should be used to ensure the structural safety and construction safety. Research conclusions：In this paper, research and analysis on 3# contact channel with pump room are made, with the [bllowing main conclusions ： （ 1 ） Practice has proved that the use of the river bottom sand freezing method is safe and reliable. But it should be possible to optimize the effective volume of the pump, reduce the sump volume, reduce the risk of freezing construction. （ 2 ） The conventional rectangular cross - section sump design is difficult to satisfy dual requirements of the freezing construction and structure of the high - pressure shear. （3） The contact channel taking the structure of the wall of variable thickness design and sump using nearly oval cross - section design, made an unexpected result which not only overcomes the problem of high pressure shear, the new structure type but also greatly improves force structure, improves structural safety affluence. （4） Currently this kind of contact channel structure type can provide the reference for the similar tunnel disign.