In this study, field measurements of the earth pressures and the main reinforcement strains were carried out at three shield tunnel linings in mud stratum reinforced by vertical jet-grouted piles during tunnel construction and post-construction. The measured strains were used to back-calculate the linings’ internal forces. The measured earth pressures and the back-calculated internal forces were compared to corresponding design values. The results indicate that the earth pressure and the internal forces increased rapidly, before exhibiting a fluctuating decrease and finally a long-term slow change, after lining assembly. The vertical jet-grouted piles were beneficial to mobilise the soil arching effect and led to the real earth pressure on the lining significantly smaller than the full overburden pressure, even with a relatively shallow buried depth. The vertical jet-grouted piles intensified the influence of backfill grouting on the earth pressure and caused the lining segments near the backfill grouting holes to continuously bear more radial pressure in the long-term. The resultant internal forces during lining assembly were large, and the Conventional Model failed to consider this element of the internal forces. The findings can provide a reference for the design and the construction of similar projects.

在这项研究中，在隧道施工期间和施工后，在由垂直喷射注浆桩加固的泥层中的三个盾构隧道衬砌中进行了土压力和主要钢筋应变的现场测量。测量的应变用于反算衬里的内力。将测得的土压力和反向计算的内力与相应的设计值进行比较。结果表明，衬砌装配后土压力和内力迅速增加，然后呈现波动下降，最后长期缓慢变化。垂直喷射桩有利于调动土拱效应，使衬砌上的真实土压力明显小于满覆土压力，即使埋藏深度相对较浅。竖向喷射桩强化了回填注浆对土压力的影响，使回填注浆孔附近的衬砌段长期持续承受更大的径向压力。衬砌装配时产生的内力合力较大，常规模型没有考虑内力这一要素。研究结果可为类似工程的设计和施工提供参考。而常规模型没有考虑内力这一要素。研究结果可为类似工程的设计和施工提供参考。而常规模型没有考虑内力这一要素。研究结果可为类似工程的设计和施工提供参考。