## 1 Introduction
### Background
GIS also allows for storing and managing the spatial information associated with the spatial feature, such as utility pipes in the relational database, that facilitate utility management. GIS technology allows for spatial analysis on a larger geospatial scale using functional and physical spatial relationships; however, it lacks information about the assets. For example, the need and interest of utility infrastructure authorities are not limited to only planning information such as alignments and profiles, but also as-design and as-built information, which is not usually available in the GIS database [11]. On the other hand, BIM can provide comprehensive and detailed as-designed and as-built information about each existing and new facility [12]. Such capability of BIM can strongly enhance the traditional contextual GIS information and analysis of utility infrastructure. However, BIM lacks geospatial capabilities, which is also very important for long utility infrastructure. Therefore, the integrated BIM-GIS workflow is suggested to be a very helpful and crucial step forward in the visualization, management, and analysis of utility infrastructure. The integrated BIM-GIS application in the utility infrastructure supports effective management of utility information over the different stages such as planning, designing, construction, and post-construction. The information in such an integrated system will be available for different applications. Many researchers have put effort to enhance the project workflow, such as heritage facility management [13; 14], supply chain management information in the construction stage [15], emergency response [16], pedestrian route planning [17], assessment of building energy [18], and climate adaption [19]. This integration area is a fast-growing trend in recent years; however, it is still in the state of infancy in construction management for the utility infrastructure. Despite the wide application of BIM-GIS in construction management, it is not easy to integrate these systems due to the difference in their modeling procedure, software, and standards. BIM and GIS have different semantic and geometry standards, limiting the optimal and smooth conversion of information models between these two systems. For instance, BIM uses industry foundation class (IFC) standards, while GIS is based on city geographic markup language (CityGML). IFC and CityGML are two widely used standards for BIM and GIS to exchange 3D geometric and semantic information. IFC represents a single 3D asset information in detail, while CityGML provides geographic asset information such as cities and infrastructure in a simple and less detailed format. Integrating BIM and GIS is highly acknowledged to be very useful to represent BIM detail information about the asset in GIS with accurate geospatial coordinates such as linking geography and geometric information, integrating ground and underground information, and incorporating detailed city model information. However, BIM-GIS application is still in its initial phase, and its integration potential is rarely utilized in the context of the utility infrastructure. This paper presents the integration of BIM-GIS for the visualization, management, and simulation of the utility infrastructure.