深埋排水调蓄盾构隧道管片1∶1力学试验系统的研发与应用

建设深埋排水调蓄隧道是缓解城市内涝问题的最有效方法之一。深埋排水调蓄隧道管片由于其直径大、外部水土荷载大、受内水压等特点,在工程实际应用前须对其受力变形特征进行研究。提出了一种1∶1平躺式原型盾构管片力学加载方法,并建立了一套管片模型试验数据采集系统。基于该试验系统,以上海苏州河段深埋排水调蓄水隧道为例,通过单环整环试验研究了埋深增加、蓄水和排水状态下管片结构内力和变形的变化规律,建立了接头抗弯刚度与偏心距之间的关系。试验结果表明:空管状态竖向收敛和水平收敛值分别为18,20mm,满管状态竖向和水平收敛值分别为78,80mm,蓄水对管片受力变形较埋深增加影响更为明显;卸载后管片变形无法恢复到初始状态,管片整体呈现非完全弹性的特点;接头抗弯刚度受管片内力影响较大并呈现空间变异性,空管状态接头抗弯刚度约为满管接头抗弯刚度的3~6倍;抗弯刚度与偏心距近似呈反比例函数关系,正负弯矩条件下均可以划分为3个阶段。

Development and Application of a 1: 1 Mechanical Testing System for Deeply-buried Water Storage and Sewage Shield Tunnel

The deeply-buried water storage and sewage tunnel serves as one of the most effective solutions to mitigate the waterlogging problems in modern cities. The segmental lining of the deeply-buried water storage and sewage tunnel usually has a large diameter and bears both heavy external soil and water pressure and inner water pressure, which makes it important to investigate its mechanical behavior and deformation characteristics before applying it in a real project. In this paper, a 1:1 ‘lying’ prototype loading method with an advanced data-gathering system for segmental lining of water storage and sewage tunnel is proposed. Based on the test system, the mechanical and deformation characteristics of the segmental lining of the water storage and sewage tunnel beneath Suzhou River of Shanghai under the conditions of increasing burial depth, water inflow and drainage were studied. The relationship between rotational stiffness and eccentricity of the joints was also explored. The test results show that the vertical and horizontal convergence deformation values of the empty tube (ET) state are 18 mm and 20 mm respectively, and those of the filled to ground (FTG) state are 78 mm and 80 mm, respectively. The rotational stiffness of joints in the ET state is about 3-6 times that of the stiffness in the FTG state, and is spatially variable. An approximately inversely-proportional relationship between the rotational stiffness and eccentricity of the joints is identified. This relationship can be divided into three stages for both sagging and hogging moment conditions.