Zhong Denghua

3D integrated modeling approach to geo-engineering objects of hydraulic and hydroelectric projects

Aiming at 3D modeling and analyzing problems of hydraulic and hydroelectric engineering geology, a complete scheme of solution is presented. The first basis was NURBS-TIN-BRep hybrid data structure. Then, according to the classified thought of the object-oriented technique, the different 3D models of geological and engineering objects were realized based on the data structure, including terrain class, strata class, fault class, and limit class; and the modeling mechanism was alternative. Finally, the 3D integrated model was established by Boolean operations between 3D geological objects and engineering objects. On the basis of the 3D model, a series of applied analysis techniques of hydraulic and hydroelectric engineering geology were illustrated. They include the visual modeling of rock-mass quality classification, the arbitrary slicing analysis of the 3D model, the geological analysis of the dam, and underground engineering. They provide powerful theoretical principles and technical measures for analyzing the geological problems encountered in hydraulic and hydroelectric engineering under complex geological conditions.

Theory and practice of construction simulation for high rockfill dam

Construction simulation for high rockfill dam (CSHRD) is the technology that takes advantage of computer simulation to observe and analyze a complex construction process, which is useful for construction design and management. In this paper, the domestic and oversea research status of CSHRD is reviewed firstly, along with introduction of their present achievements and deficiencies, and the CSHRD theory is also described. Then, considering the influence of many stochastic factors, integrated simulation for high rockfill dam construction (HRDC) is presented with technologies of cycle operation network (CYCLONE) and computer simulation. It rationally combines two subsystems in HRDC, namely haulage and placement of rockfill subsystem, which reflects the actual construction objectively. Important parameters, such as the haulage intensity and traffic density, are obtained, and the process of CSHRD is represented intuitively in dynamic visualization. All of these help engineers to make rapid decisions in HRDC scientifically.

Construction schedule risk analysis of high roller-compacted concrete dams based on improved CSRAM

The applied technology of high roller-compacted concrete (RCC) dams is quite complicated because of various risk factors, including the weather condition, supply of concrete aggregate, efficiency of transport machinery and dam surface machinery, and so on. In order to ensure the comprehensiveness, accuracy and objectivity of construction schedule risk analysis, a mathematical model called improved correlated schedule risk analysis model (CSRAM) is proposed in this paper. This model takes into account not only the construction features of high RCC dams, but also the stochastic variations of risk factors with the construction schedule, as well as their comprehensive effects. Using Monte Carlo method to solve this model enables the completion probability of a high RCC dam construction within plan time, and uncertainty analysis of risk factors. Compared with the conventional CSRAM, the improved CSRAM has higher completion probability and more convergent distribution of a simulation period, making analysis results more accurate and closer to actual engineering conditions. Among the ten risk factors selected, efficiency of dam surface machinery and proficiency of workers are found to be of the maximum uncertainty.

An approach to 3D NURBS modelling of complex fault network considering its historic tectonics

Fault disposal is a research area that presents difficulties in 3D geological modeling and visualization. In this paper, we propose an integrated approach to reconstructing a complex fault network (CFN). Based on the non-uniform rational B-spline (NURBS) techniques, fault surface was constructed, reflecting the regulation of its spatial tendency, and correlative surfaces were enclosed to form a fault body model. Based on these models and considering their historic tectonics, a method was put forward to settle the 3D modeling problem when the intersection of two faults in CFN induced the change of their relative positions. First, according to the relationships of intersection obtained from geological interpretation, we introduced the topological sort to determine the order of fault body construction and rebuilt fault bodies in terms of the order; then, with the disposal method of two intersectant faults in 3D modeling and applying the Boolean operation, we investigated the characteristic of faults at the intersectant part. An example of its application in hydropower engineering project was proposed. Its results show that this modeling approach can increase the computing efficiency while less computer memory is required, and it can also factually and objectively reproduce the CFN in the engineering region, which establishes a theoretical basis for 3D modeling and analysis of complex engineering geology.

The Application of Computer Graphic Technology on Monitoring Roller Compaction Quality of Rock-fill Dam

This article technically analyzes the application of computer graphics on “automatic monitor and feedback control system for roller compaction quality of rock-fill dam” by anatomizing the monitor process. The application and software implementation of computer graphic technology enable the monitor system for roller compaction quality of rock-fill dam to realize drawing of tracks and strips of rollers, calculation and display of control parameters of roller compaction, which achieves the goal of visual monitor on roller compaction quality.This article technically analyzes the application of computer graphics on “automatic monitor and feedback control system for roller compaction quality of rock-fill dam” by anatomizing the monitor process. The application and software implementation of computer graphic technology enable the monitor system for roller compaction quality of rock-fill dam to realize drawing of tracks and strips of rollers, calculation and display of control parameters of roller compaction, which achieves the goal of visual monitor on roller compaction quality.