Numerical Study On The Construction Order Of Anti-slide Piles For Landslide Control Engineering

Taking the Baihuyan Landslide as an example, this paper firstly collected the regional geological information to analyze the geological condition and a detailed investigation. Then master the characteristics of landslide and deformation mechanism. Through the software of MAIDAS/GTS, establish models with different shelving and different excavation, then obtain the main triggering factors of the slope and reasonable construction orders. There are two kinds of model according to construction process. The first kind of model simulates the slope before construction, including the initial slope model and model with the slope toe excavated. The other kind of model simulates the construction stages. Two kinds of model were analyzed after construction: actual construction condition and compared construction condition. There are four types of construction, namely total excavation and then the pile, one hop pile excavation, double jump pile excavation and excavation on the both sides.The main results are the following:(1) After the excavation slope toe, the maximum displacement, principal stress and strain of two models before the construction move from the east to the central position. the maximum principal stress distribute intensely and widely in the slope toe. The maximum shear strain distributes intensely in the weak layer. Slope toe excavation leads to redistribution the stress and strain, which cause instability of slope foot and drive the whole sliding of the landslide mass.(2) Comparison between two models before the construction shows that with the same geological conditions, unreasonable excavation lead to instability of the slope which is stable originally.(3) The simulation of actual construction conditions shows that the maximum principal stress concentrated in the pile of excavation, excavation piles were located in the main sliding area on the slope disturbance with poor stability, which is very easy to lead large displacement deformation, therefore, the actual construction order was unreasonable.(4) Comparing different construction sequence of construction conditions, it was found that double jump pile excavation and working conditions on both sides of the excavation had the minimum of max displacement, stress and strain, and the stress concentration is not obvious, with less disturbance of slope stability and high stability factor, which had reasonable construction order. Therefore, the Baihuyan landslide construction should choose the construction order on both sides of excavation and pile excavation jump combination.(5) In determining the order of the landslide construction, there are three facts to be considered mainly: the disturbance of the slope especially the scale of free surface, the influence of sliding force and anti-sliding force and construction period.