Analysis On The Settlement And Stability Of Freeway Soft Soil Foundation Treated With Gravel Pile

Relied on the freeway from Bazhong to Nanbu which is under construction, this paper analyzes the settlement and stability of its foundation treated with gravel piles in swale areas by means of site survey as well as numerical simulation.By setting up sensors at the construction site and analyzing on the collected data about the process of embankment construction, this paper figures out that settlement as well as horizontal displacement of the soft soil foundation in swale areas increase as the upper loads increase, and both are susceptible to construction speed.Based on the application of PLAXIS—a certain professional geotechnical software, this paper establishes a nonlinear finite-element model that reflects the plane strain of soft soil foundation treated with gravel piles, to compute the mechanic reactions of two typical cross sections, such as settlement, horizontal displacement, slope stability and so on. While comparing the computational results with site-survey data, this paper consequently optimizes the space between different gravel piles and the diameter of gravel piles. In this way, this paper reaches such conclusions:confined within a certain scope, while the space between different gravel piles augments or the diameter of gravel pile diminishes, the settlement of foundation largely increases and the slope stability however only decreases slightly; on the other hand, while the space between different gravel piles diminishes or the diameter of gravel pile increases, the settlement of foundation remarkably decreases and the slope stability increases slightly.The appropriate design method for the gravel-pile-treated freeway subgrade in swale areas proposed in this paper, in some sense, can provide a guide for similar design and construction works.