Influence and repair of underground engineering construction on karst flow field

Abstract

Engineering construction changes the groundwater flow field and endanger the safety of buildings. Taking the large-scale underground complex along Jinan Jingshi Road as an example, the impact of engineering construction on the groundwater seepage field is obtained by numerical simulation, and the groundwater flow field repair models are established. These results show that the underground spatial structure will block the normal movement of groundwater, and will reduce the bearing capacity of the foundation after the groundwater level is raised. After adding diversion measures to the underground space, the water level at the upstream surface will decrease with time, and the closer it is to the natural state, the slower the water level attenuation rate is. Due to the difference in the stratum structure, there is a great difference in the time when the backwater level basically drops. The number of diversion wells required to repair the flow field under different geological conditions has a negative correlation with the structural parameters of diversion geometry. The established equation for predicting the number of diversion wells fully reflects the complexity and variability of geological conditions in karst areas. In addition to the structure of the fluid conducting geometry, the hydraulic gradient and permeability coefficient of the surrounding rock also affect the water conducting capacity of diversion measures. The permeability coefficient controls the speed of the water conducting rate, while the hydraulic gradient controls the occurrence of water conducting behavior. The implementation of diversion measures can reduce the impact of engineering construction on the groundwater environment and ensure that the impact of underground engineering construction on the water environment is controllable.

Keywords

• karst area
• underground construction
• groundwater
• seepage
• flow field repair