河道内大管径小曲率顶管对护岸的影响研究

Research on Impact of Large-diameter Small-curvature Pipe Jacking in River on Bank Protection

摘要:

随着上海城市化率的不断提高，市政工程中采用的大管径雨污水管也逐渐增多。受日益紧张的城市用地空间限制，部分市政顶管工程转向河道内，沿河底敷设管道进行小曲率顶管，并通过土体加固和增加压重等措施降低顶管施工对周边防汛设施的影响。为定量研究分析河道内大管径小曲率顶管对河道护岸的影响，结合工程实例，建立了plaxis二维有限元模型进行数值模拟，证明了工程采用的河底下方MJS预加固再顶管的施工方法合理可行，对河道护岸影响较小，并通过比较模型拟合值与施工期监测数据，验证了模型的有效性。

Abstract:

With the continuous improvement of urbanization rate in Shanghai, the use of large-diameter rainwater and sewage pipes in municipal engineering is also gradually increasing. Restricted by the increasingly tight urban land space, some municipal pipe jacking projects have turned into the river channels, where the small-curvature pipe jacking is carried out by laying pipes along the riverbed. And the impact of pipe jacking construction on the surrounding flood control facilities is reduced through the measures such as soil reinforcement and increasing the weights. In order to quantitatively study and analyze the impact of large-diameter small-curvature pipe jacking on the river bank protection, a two-dimensional finite element model of Plaxis is established for numerical simulation in combination with the engineering examples. It is proved that the construction method of MJS pre-reinforcement and then pipe jacking below the riverbed used in the project is reasonable and feasible, and has a relatively small impact on river bank protection. The effectiveness of the model is verified by comparing the fitting values of the model with the monitoring data during the construction period.