Division of engineering geological strata, building of 3D geological structure and its application in urban planning and construction in Xiong'an New Area

This paper is the result of urban geological survey engineering.

Objective In order to standardize the division of engineering geological strataandbuild the three-dimensional engineering geological structure model of Xiong'an New Area, it is better to exchange and utilization of engineering geological and geotechnical engineering data.

Methods In this paper, based on the data of engineering geological survey, the characteristics of Quaternary strata is expounded in Xiong'an New Area, and engineering geological zoning is carried out. The engineering geological strata of soil in 100 meters depth and their substrata are divided, and the spatial distribution and engineering characteristics of each stratum are analyzed. The three-dimensional engineering geological structure of Xiong'an New Area is builded, and its applicationin urban construction is discussed.

Results The results show that the Holocene floor depth is generally 7-16 m, the Late Pleistocene floor depth is generally 50-60 m, the Middle Pleistocene floor depth is generally 70-80 m, and the Early Pleistocene floor depth is about 140-190 m in Xiong'an New Area. The Quaternary strata can be divided into the alluvial and proluvial plain engineering geological subarea, the alluvial and lacustrine plain engineering geological subarea and alluvial plain engineering geological subarea. The stratum of 100 m depth can be divided in to 18 engineering geological strata, of which ①-④ strata are Holocene (Q_h), ⑤-⑨ strata are Upper Pleistocene (Q_p³), ⑫-⑮ strata are Middle Pleistocene (Q_p²), and ⑯-⑱ strata are Lower Pleistocene (Q_p¹). The three dimensional engineering geological structure model of the study area is constructed, which can intuitively show the stratigraphic distribution and structural characteristics within the depth range of 100 meters underground in Xiong'an New Area.

Conclusions Through the division of engineering geological layer groups and the establishment of three-dimensional engineering geological structure model, it can serve the top planning and design of Xiong'an New Area, the evaluation of site stability and suitability, the selection of natural foundation and pile foundation bearing layer, subway tunnel line selection and site construction, etc., providing an important geological basis for high standard and high-quality construction of Xiong'an New Area.