PKPM series consists mainly of 3D modeling software for PMCAD and SPASCAD. Both modules have focused on early in the design of its internal data structure is not the same, the end user interaction logic and subsequent processing will have a big difference The article attempts to analyze the internal mechanism from the two software similarities and differences to enable a deeper understanding in the use.

The Building Information Modeling(BIM), possessing powerful architecture digitizing capability, has been increasingly applied in construction fields and processes during the life cycle.In the architecture designing process, the building information model should be modified several times before perfectly forming a complete project design scheme, and those modification information can provide references for the optimization of the design scheme.However, Revit can not provide detailed recordings or eligible traces of those intermediate state information.In order to achieve all-the-way tracking and improve efficiency of the model modifications, this paper presents a version management scheme of building information modeling based on event monitoring mechanism.Research shows that such a version management scheme can effectively track modification information of various model versions, which facilitates the management of building information modeling.Meanwhile, the version management scheme adopts the mechanism of merging operation information to clear the redundant operation of the same object, which shortens the execution time of the model from the initial state to the target state, and plays a significant role in acceleration.

This paper introduces the design scheme of the BIM-based energy consumption monitoring platform for ventilation and air conditioning of Lanzhou rail transit. The platform collects data for the station, including the energy consumption and operation status of environmental control equipment in large system, the station public area environment, passenger flow and outdoor weather. All data can be visualized through BIM, to monitor the real time energy consumption and cooling effect of ventilation and air conditioning equipment in large system. Meanwhile, the method of data analysis and processing is adopted to detect the monitored data. Taking the Dongfanghong Square station of Lanzhou rail transit as a pilot, this paper explores the optimal control method of ventilation and air conditioning energy saving, and realizes the effective combination of energy consumption analysis and optimal control, which will effectively improve the energy-saving management and control ability of environmental control system in urban rail transit operation stage.

ACA is the abbreviation of AutoCAD Architecture. It is based on AutoCAD, but designed for Architectural design. It is often called AutoCAD for architects. Using DOT NET API and basing on ACA's intelligent object model, we have developed an application module especially for structural engineers. The structural functions such as creating layout grids, placing members and loads etc are all included. The model created by the structural module can be directly imported to structural analysis software like ETABS to do the analysis job. It is designed for integrating architectural and structural design and analysis. This paper can be used as a reference for the application of BIM technology.

Contrast to the traditional paper-based information representation methodology which uses 2D graphic primitive elements such as point, line, face etc., the application of 3D digital technologies in A/E/C(Architec-ture/Engineering/Construction) domain significantly improves the efficiency of construction information communications and has become a key technical support of BIM (Building Information Modeling). The various types of 3D geometric representations can be classified into solid model, surface model and framework model, each of which can be applicable in specified application areas and scope. To meet the requirements of BIM applications in different phases of A/E/C, a methodology of 3D solid modeling and converting it into surface model of IFC-based BIM is proposed in this paper, which adopts AutoCAD graphic engine. Its feasibility is verified by some tests.

In order to adapt development of building's, SpasCAD is rebuild. This version improves primarily stability, easy to use and adds support for new technology. New Inspection and display system is designed according to characteristic of building, which can continue to analyze SpasCAD's model. This version provides new function for develop professional software. In this paper, important improvement and new specialty for SpasCAD are introduced.