Soil slope is one of the main parts of the road engineering. The stability of the slope is an essential prerequisite to ensure the safe operation of road transport. In seasonal frozen regions, shallow landslide hazards in soil slopes usually happen, which pose a serious threat to road safety operations. During the melting process, there forms stagnant water lubrication between the melting soil and freezing soil interface, which constitutes the weak interface of landslide hazard. Special methods to form the freezing – thawing (F-T) surface is designed, and takes consider the interface strength as the foundation of experimental tests, then opening to research the soil slope stability. Safety factor modification of the soil slope is presented. The conclusions of this paper present well theoretical and applied value to the regional slope failure analysis.

The establishment of an effective finite element model (FEM) for the bridge structure is essential in the health monitoring system of urban grade separation bridge. It inevitably exist inconsistency of response between the FEM and practical structure due to various uncertain factors in the modeling and analysis procedure. Therefore the updating of FEM is necessary. A uniform design-based static model updating method is proposed in this paper, the allowable range of model parameters (the number is ) is divided into several levels (the number is ), the model updating method is transformed into a -factors and -levels test design. Several groups of combined parameters are selected to conduct test through finite element calculation based on the principle of uniform design method, and the optimal parameter group is obtained. This method is applied to the model updating of a complicated special-shaped urban grade separation bridge, and a perfect FEM with a good agreement with measured data is obtained. It confirms the feasibility and superiority of this method.

A support vector machine (SVM) optimized by particle swarm optimization (PSO)-based damage identification method is proposed in this paper. The classification accuracy of the damage localization and the detection accuracy of severity are used as the fitness function, respectively. The best and can be obtained through velocity and position updating of PSO. A simply supported beam bridge with five girders is provided as numerical example, damage cases with single and multiple suspicious damage elements are established to verify the feasibility of the proposed method. Numerical results indicate that the SVM optimized by PSO method can effectively identify the damage locations and severity.