# Geotechnical Property Modeling and Construction Safety Zoning Based on GIS and BIM Integration
## 1 Introduction
### Geographic Information System (GIS) and Building Information Modeling (BIM)  
Geographic information system (GIS) manages and analyzes the spatial information about assets based on geomatics techniques. GIS is an information technology system that has all the features such as storage of spatial information in the relational database. GIS stores all the information such as location, spatial, and non-spatial information about a spatial facility in the database that provides a significant advantage in the spatial and temporal analysis [35]. For example, it can store the geotechnical parameter information in a geodatabase that can be used for the spatial distribution for the whole area. For instance, the standard format for exchanging geographical and semantic information for GIS data is City Geography Markup Language (CityGML). CityGML is the open data model and standard format that represent the contextual GIS data in a structured way and can be shared by many application [36].  
BIM simulates the physical model in a virtual environment called the building information model that contains geometric and non-geometric information [37,38]. The BIM model characterizes the graphical model with non-graphical information such as materials information, properties of materials, and the quantities of the materials [38]. By appending this information with the geometry, the engineering analysis can be implemented with ease of decision-making at different stages of the projects [32]. The Industry Foundation Class (IFC) is considered to be an open standard format for exchanging graphical and 3D semantic information for BIM [28,39]. It has an objected-oriented hierarchy containing geometry information with predefined attributes and relationships. In the beginning, the IFC standard targeted building, while it is now extending towards the infrastructure models such as [28] extends the IFC schema for the tunnel infrastructure. The IFC information can be represented with the use of compact and well suited EXPRESS data definition language [40]. Furthermore, the BIM data representation in IFC format allows the user to view, map, and process the information using IFC viewers or other compatible software [41]. The existing IFC classes and their relationships can be used to store a new type of information under the IfCrPropertySet defined in the IFC standard [28,39,42].  
BIM model contains detailed information about the object geometry and semantics, however, it lacks the surrounding information [42]. Spatial information is needed in the BIMmodel such as the topographic information that can be provided by GIS technology [32; 43]. The integration of BIM and GIS in construction management is in the initial stages but a fast-developing trend in recent years. BIM and GIS have been integrated for multiple cases such as improving the visualization of supply chain management during construction [44], heritage management [45; 46], emergency response and pedestrian route planning [47; 48], energy assessment [49], and climate adaption [50]. From previous studies, researchers have put much effort into the integration techniques, and several methods are proposed to address various problems [32; 33]. Many researchers have worked on the integration of IFC and GIS model such as CityGML using bi-directional linkage for classes [51; 52]. Some of the previous research on the integration of BIM and GIS has been reviewed in the next subsection.