关键词: 泥水平衡盾构, 数值模拟, 高架桩基, 加固措施, 施工参数

Abstract:  To investigate the deformation control strategy of a superlargediameter shield laterally crossing existing pile foundation at a short distance, a case study is conducted on the Jiluo road Yellow river tunnel in Jinan, China, a refined numerical model is developed to simulate the shield tunneling process based on onsite monitoring data and construction parameters and the impact of adjacent embankment on the pile foundation response during the process of the shield tunneling. Furthermore, the application effects of reinforcement measures under various construction parameters are comparatively analyzed and the adaptability of the comprehensive reinforcement measures of isolation pile strengthening + highpressure jet grouting pile reinforcement + pregrouting reinforcement using steel flower tube under various construction conditions is investigated. The results show the following: (1) The adjacent embankment will raise the slope of the pier platform after laterally crossing the early driven tunnel, and this effect will occur at a certain time under specific construction conditions. (2) On the premise that the construction parameters are well controlled, adopting corresponding measures to strengthen the pile can better restrict the influence of early soil disturbance on the pile foundation; however, the final application effect of the reinforcement measures is limited. (3) The variance of different reinforcement measures in controlling the transverse horizontal displacement of pile foundation is more obvious than that in the longitudinal direction. (4) The influence of slurry pressure on the application of the reinforcement measures is considerable, while the effect of grouting pressure is very limited in this respect.

Key words: slurry balance shield, numerical simulation, viaduct pile foundation, reinforcement measure, construction parameters