Karst is a common geological condition in engineering construction. In order to study the influence of karst cave and boundary condition on the analysis of free field ground motion in karst area, viscoelastic artificial boundary was studied in free field ground motion analysis of karst region, a three-dimensional finite element model whose dimension is 1000 m × 1000 m × 500 m was set up, characteristics of ground motion in karst region were studied on the basis of viscoelastic artificial boundary, as well as the influence of karst cave on displacement, velocity and acceleration were considered. The results show that, natural frequencies of free field were decreased at different degrees after viscoelastic artificial boundary was adopted. Compared with the response of free field without karst cave, the variation trend of maximum displacement, maximum velocity and maximum acceleration were all spread around the karst cave, the biggest change of maximum displacement, maximum velocity and maximum acceleration appeared on the top of karst cave. Compared with spectrum curve of free field without karst cave, the amplitude difference of free field with karst cave was significant in low order frequency, and was opposite in high order frequency, the influence of karst cave on vertical direction is bigger than horizontal direction, which can provide reference for construction of karst region.

LOKASI: Ruang Koleksi Umum
Rak: 2