高水压泥水平衡盾构掘进模型试验平台的研制与应用

为了实现可在2.0 MPa高水压环境下开展盾构试验研究的基础试验条件,结合拟建的琼州海峡隧道工程背景,充分调研了国内外盾构模型机研究成果,并根据试验研究的需求,研发了高水压多功能泥水平衡盾构模型试验平台。试验平台研制过程中攻克了在缩尺盾构模型机中实现泥水循环功能的问题,解决了高水压(2.0 MPa)下盾构机以及土箱整体强度和密封问题,实现了盾构姿态改变、变覆土高度等功能。按照一定的试验先期准备步序,在不同水压条件下,对泥水平衡盾构开挖过程中盾构姿态动态变化规律进行了模型试验研究。试验平台包括模型土箱、盾构模型机、液压泵站、电控柜、控制台、泥水循环系统等部分,可在200 m水头的高水压条件下进行泥水盾构施工的模型试验。研究结果表明:自主研发的泥水平衡掘进模型试验平台可在高水压条件下正常进行工作,并可进行与泥水盾构施工相关的模型试验;盾构姿态角改变量与盾构掘进距离的线性拟合结果表明,二者的拟合精度较高;随着试验水压的升高,在水平方向以及竖直方向上盾构姿态调整的难度逐渐增大;通过有土环境与无土环境的对比可知,高水压与地层反力的双重约束对盾构姿态控制提出了更高的要求。

Development and Application of Model Test Platform for Slurry Balance Shield Under High Water Pressure

In this study, the necessary test conditions for shield-related experimental research in a 2.0 MPa high-water-pressure environment, combined with the engineering background of the proposed Qiongzhou Strait Tunnel, were investigated. The research results for local-and foreign-model shield machines were analyzed, and based on the requirements of this experimental study, a model test platform for the high-pressure multifunctional slurry balance shield was developed. During the development of the test platform, the challenge of achieving the slurry circulation function in the scale model shield machine was overcome, and the shield machine was subjected to high water pressure (2.0 MPa). In addition, the overall strength and sealing of the soil box were determined, and the functions of the shield attitude change and variable cover soil height were achieved. According to pretest preparation procedures under different water pressure conditions, model tests were conducted on the dynamic changes in the shield attitude during the excavation of the slurry balance shield. The system mainly consisted of a model box, model shield, hydraulic pumping station, electric control cabinet, console, and slurry circulation system. This test platform can be used to perform model tests on slurry balance shield construction under high water pressure conditions of 2.0 MPa. The test results show that the model test platform for self-developed slurry balance tunneling can effectively work under high water pressure conditions and can be used to perform model tests related to slurry shield construction. The change in the shield attitude angle can be linearly fitted to the shield tunneling distance, and the fitting accuracy of the two parameters was high. With an increase in water pressure, the difficulty in adjusting the attitude of the shield in the horizontal and vertical directions increases gradually. Through the comparison of the soil and soilless environments, higher requirements for the attitude control of shields are required under dual constraints of high water pressure and formation reaction forces.