Seepage Flow Model and Deformation Properties of Coastal Deep Foundation Pit under Tidal Influence

Abstract

As the coastal region is the most developed region in China, an increasing number of engineering projects are under construction in it in recent years. However, the quality of these projects is significantly affected by groundwater, which is influenced by tidal variations. Therefore, the regional groundwater dynamic characteristics under tidal impact and the spatiotemporal evolution of the seepage field must be considered in the construction of the projects. Then, Boussinesq function was introduced into the research to deduce the seepage equation under tidal influence for the coastal area. To determine the spatiotemporal evolution of the deep foundation pit seepage field and the coastal seepage field evolution model, numerical calculations based on changes in the tidal water level and seepage equation were performed using MATLAB. According to the developed model, the influence of the seepage field on the foundation pit supporting structure in the excavation process was analyzed through numerical simulations. The results of this research could be considered in design and engineering practice.

Numerical Simulation of Soil Displacement and Settlement in Deep Foundation Pit Excavations Near Water

“…(1) The current constitutive model cannot accurately reflect the deformation law of all soils in the excavation stage (Chen et al [12], Li et al [16], and Zhang et al [32]). The parameters used in the calculation depended significantly on the geological prospecting data of the project, and the interval between drilling holes was 50~100 m, which cannot accurately describe the stratification change of the excavation surface and surrounding soil.…”

“…The results showed that the FS value increases with an increase in the impervious aquifer thickness and undrained shear strength but decreases with an increase in the pressure bearing capacity and excavation width of the foundation pit. Li et al [16] researched foundation pit engineering under the action of tides in coastal areas, The Boussinesq function was introduced to derive the seepage equation under the influence of tides in coastal areas, and MATLAB was used to analyze the influence of the seepage field on the supporting structure of foundation pits during excavation. Xue et al [17] analyzed the periodic changes in the seepage pressure of the foundation through field monitoring and numerical simulation using a sluice.…”

Research on the Influence of Groundwater in Coastal Areas on the Stress and Deformation Characteristics of Integrated Pipe Gallery

“…Bhattacharya and Dutta [6] found that in the process of tunneling in the presence of groundwater table, seepage force will be generated, which will lead to the decrease of rock mass stability. The results of Li et al [7] indicated that the dynamic characteristics of regional groundwater and the temporal and spatial evolution of seepage field under the influence of tides must be considered in engineering construction. The results of Deng et al [8] showed that when excavating tunnels in water-rich soft rock formations, the infiltration of groundwater greatly reduced the strength of the soft rock.…”

Study on Supporting Structure Performance of Deep Soft Soil Foundation Pit near Sea under Waves, Tides, Vibration, and Unbalanced Loads

“…Many researchers have studied the construction of foundation pits in coastal soft soil strata. Li et al [10] used MATLAB to determine the spatiotemporal evolution of the deep foundation pit seepage field and the coastal seepage field evolution model and then analyzed the influence of seepage field on the foundation pit supporting structure in the excavation process through numerical simulations. Qin et al [11] studied three special supporting methods adopted in the coastal foundation pit construction, and they effectively solved the challenges in a coastal soft soil region, i.e., the high ground water level, low inner friction angle, and cohesion.…”