Fan Xue

An Optimization-Based Semantic Building Model Generation Method with a Pilot Case of a Demolished Construction

Emerging technologies like massive point cloud from laser scanning and 3D photogrammetry enabled new ways of generating ‘as-built’ building information models (BIM) for existing buildings. It is valuable but also challenging to generate semantic models from point cloud and images in automated ways. In this paper, we present a novel method called Optimization-based Model Generation (OMG) for automated semantic BIM generation. OMG starts from a semantic BIM component dataset and a target measurement such as point cloud, photographs, or floor plans. A fitness function is defined to measure the matching level between an arbitrary BIM model and the target measurement without object recognition. Combinations of digital components are then extensively generated as building models regarding semantic constraints. The fittest model that matches the target measurement best is the result of OMG. The proposed method was demonstrated in reconstructing a 3D model of a demolished building. Advantages of OMG include high-level automation, low requirement on measurement, relationship discovery for components, reusable component libraries, and scalability to new environments.

Smart gateway for bridging BIM and building

Building information modeling (BIM) has been emerging as a digital platform to create, exchange, and manage the information in a construction project. Over the past decades, researchers have explored various techniques, including laser scanning and sensing devices, to keep the BIM up-to-date. Their efforts have been conceptualized as bridging BIM and building (BBB). In the BBB framework, a key component is the smart gateway which is the middleware to ensure information input/out between the physical project layer and the BIM layer. The aims of this research is multifold: (1) to highlight the importance of smart gateway for BBB; (2) to generate the definition of the smart gateway based on existing gateways in other industries; and (3) to describe the essential functions of the smart gateway based on the BBB framework. Theoretically, with four major functions including device configuration and management, data filtering and processing, temporary information storage, and supplementary information input, the proposed smart gateway can significantly facilitate the integration between the physical project information with BIM. Future research will be conducted to develop and implement a prototype of the smart gateway in actual construction projects where multi data-acquisition devices are used.

Bridging the Cyber and Physical Systems for Better Construction: A Case Study of Construction Machinery Monitoring and Utilization

It has been widely accepted that developing and maintaining a cyber system (e.g. Building Information Modeling) representing the corresponding physical system is a promising approach to improve decision-making in construction. However, to bridge the bi-directional coordination between the virtual and the physical system is the prerequisite for the improvement, yet this is the most challenging part for researchers and practitioners. Using tower crane as a case study, the primary aim of this study is to propose a cyber-physical system by articulating its system structure, bridging technologies, and its computational applications. Particularly, a smart core is developed to integrate real-time information on physical machinery on site with their ‘cyber twins’ in virtual, which is developed as a web-based platform. A LEGO® tower crane is built and simulated in lab, showing the cyber and physical systems can be well bridged to facilitate safety management and resource utilization in construction projects.

The Fusion of GIS and Building Information Modeling for Big Data Analytics in Managing Development Sites

Due to increasing complexity of contemporary site development, more information about sites themselves and their related environmental, geographical, and surrounding infrastructure is highly desired to support informed decision-making. Fusion of Geographic Information Systems (GIS) and Building Information Modeling (BIM) to support decision-making in site development has gained momentum from both academia and practitioners. Nevertheless, innovative applications of GIS and BIM integration are yet to be fully explored. Using several cases in Hong Kong Special Administrative Region (SAR), this article demonstrates how to integrate GIS and BIM to derive big data for decision-making in construction logistics and supply chain management (LSCM) and construction waste management in site development. In addition, this article proposes a conceptual framework of integrating BIM and GIS for better site development and urban management. The cases in this article not only shed light on big data analytics in a site development setting but also provide useful references to GIS and BIM fusion for better urban management.

Developing an Open Access BIM Objects Library: A Hong Kong Study

Design in a Building Information Modelling (BIM) environment, in a sense, is similar to playing Lego; a designer puts various objects together to form his/her design. The availability of BIM objects, or say the Lego pieces, is one of the most critical issues for promoting BIM implementation. Existing BIM objects, however, are far from comprehensive. Neither is there a Oone-size-fits-for-allO objects library; one has to develop a localised library suiting a particular construction setting. The efforts to tailor-make such a library incur huge costs, which partly explains the mundane BIM implementation in many economies. This paper explores an effective approach to develop an open access BIM objects library focusing on Hong Kong. It does so by (a) determining an ontology-based structure of the library; (b) defining the BIM objects parameters; (c) developing an object processing module (OPM) to unify and integrate the objects from other sources; and (d) exploring the sustainable development of the library. Although further studies are desired to bring it into full reality, the BIM objects library is expected to facilitate building design and information management in a BIM environment. It will also promote BIM implementation in Hong Kong and serve as useful references for other economies.