Characteristics of discontinuities in Heifangtai landslide area in Gansu, China

Abstract

Loesses are widely distributed all over the world, especially in China. Meanwhile, long-term agricultural irrigation and extreme climate changes have led to frequent geological disasters in the Heifangtai area of Lanzhou, Gansu, China. Of these, landslides are one of the most frequent types of disasters that are harmful to humans and the environment. A landslide is closely related to the lithology, structure, and groundwater of the site and consists of a combination of structure units divided by discontinuities, such as faults, joints, and fissures. Therefore, geological surveys, engineering drilling, and trenching are typically used to identify the stratum lithology, structure, and groundwater in order to visually display underground information within a limited depth range. However, these methods have disadvantages. In particular, geological surveys can only describe geological phenomena on the surface, while the cost of drilling and trenching may be high, along with the inefficiency of exploration. In this research, the integrated geophysical exploration method was used to analyze the hidden joints, cracks, and other discontinuities and geophysical features of the discontinuities. The results were verified by trench exploration, and large amounts of underground information were obtained, especially the spread and distribution of discontinuities in landslide areas. Such information can be effectively used for carrying out and providing meaningful experiences and lessons in future comprehensive geophysical processing and interpretations related to the prediction and evaluation of landslides.