Abstract: The integrated development of urban areas above and below ground is becoming an inevitable trend in contemporary urban development. The carrying capacity of the 3D geological environment of the city is an indispensable component of urban master planning. This article uses Zhengzhou city as an example and utilizes data such as engineering geology, hydrogeology, the current status of underground space development, and surface ecological and transportation environments to create a 3D model of Zhengzhou city's geological environment. Subsequently, relevant indicators are selected, and the entropy-weighted TOPSIS method is used to evaluate Zhengzhou city's geological environment carrying capacity. The results indicate that the carrying capacity of the developed areas in Zhengzhou city is the weakest, the carrying capacity in the northern riverside areas is relatively weak, the central urban areas have a moderate carrying capacity, and the southern areas have relatively strong carrying capacity, providing a reference for the development of underground spaces in Zhengzhou city.

Key words: 3D geological modeling, 3D geological environment bearing capacity, entropy weight TOPSIS analysis