Protection and Development Practice of Underground Space in River Delta Area

The estuarine delta area is a special geographical area that developed under the interaction of river, sea, and land. The development of the underground space in the estuarine delta is restricted by the conditions of the soft soil, the construction investment, and so on. For cities in the estuarine delta area, it would be essential to conduct the investigation and evaluation of the underground soil conditions, improve the layout of underground infrastructure facilities, and make accurate predictions of the development scale of underground space. This paper, taking Nansha New Area (Guangzhou, China) as an example, uses high-density drilling data to make a survey and draw "the base map" of underground space, and conducts a high-accuracy evaluation of the suitability of underground space development. Based on this, it proposes a value map of development and protection in different zones and aims to achieve the improvement "from underground to above ground" considering both the urban safety and economy. Additionally, it gives co-ordination of the different prediction model of the development of the underground space between the government and the market, and keeps the balance among the land value, the construction cost and the ecological protection during the construction process, which aims to develop the underground space in the estuarine delta area in a more scientific and intensive approach.