Aiming at the deformation characteristics of surrounding rocks in underground powerhouse area of a hydropower station in Western China, the finite difference method is used for numerical calculation, and a assistant modeling software is used to realize the refined modeling of complex surface, which effectively improves the simulation accuracy. The results show that the stress level of surrounding rocks is low, the deformation of surrounding rocks is small, and the surrounding rocks is basically stable. However, the plastic zone of surrounding rocks has the trend of transfixion, so it is necessary to adjust the spacing of powerhouse.

Traditional analysis of landslide evolution discipline requires particular on-site investigation, which not only consumes a lot of manpower and material resources, but is also very inefficient. With the development of small drone aerial photography technology, a method based on the whole area landslide measurement becomes possible. This paper uses the rapid development of digital photogrammetry technology in recent years to monitor the surface deformation of the Qinyu landslide, and conducts an in-depth study of its evolution. The results show that the evolution of the Qinyu landslide is inherited and different in time and space. The reconstruction of the three-dimensional model greatly simplifies the traditional on-site investigation, and it also provides new methods and ideas for landslide monitoring.

Initial geostress field is an important factor affecting the stress distribution, displacement and failure mode of surrounding rock of underground engineering, and is also one of the important indexes of design for underground works, especially large hydropower projects. At present, the method to obtain the geostress field is mainly based on measured in-situ stress, however some projects are lack of in-situ stress measurement data. To solve this problem, we inversed regional tectonic stress field firstly, and then extracted the boundary load of the project area from the fitted regional tectonic stress field and embedded the underground cavern to be studied in the calculation model to carry out the numerical calculation of the geostress field of the project area. The results show that the direction of regional tectonic principal stress is NNE∼NE, and the average maximum horizontal tectonic stress is about 5.0MPa. The direction of the maximum principal stress in the project area is generally the same as that of the regional tectonic stress field, which indicates that the valley stress field is determined by the regional tectonic stress field. However, due to the influence of river incision, the geostress field of the project area redistributes, and has the basic characteristics of principal stress direction deflection and stress differentiation. The research results provide a basis for the subsequent study of the stability of underground caverns, and have a certain reference value for the method of obtaining initial geostress field of a project without measured in-situ stress.