Abstract To promote sustainable development of performance evaluation of high-speed railway construction projects, to summarize the gains and losses of construction projects in time, and to further improve project management, project quality and fund use efficiency, the performance evaluation index system is designed and developed. It’s based on existing theoretical research results and domestic and foreign practical experience, according to the... To promote sustainable development of performance evaluation of high-speed railway construction projects, to summarize the gains and losses of construction projects in time, and to further improve project management, project quality and fund use efficiency, the performance evaluation index system is designed and developed. It’s based on existing theoretical research results and domestic and foreign practical experience, according to the personalized characteristics of highspeed railway construction projects. Combined with entropy method, CRITIC (Criteria Importance Though Intercrieria Correlation) method and catastrophe theory, a performance evaluation model of high-speed railway construction project is constructed by combining weighted and catastrophe sequence. The main idea of this evaluation method is to get combined weights of each index by combining the entropy evaluation method with subjective and objective factors, and then it judges the performance level of high-speed railway construction projects by combining mutation sequence method. The example analysis shows that performance of high-speed railway construction projects is mainly reflected in three stages, namely design and construction, completion acceptance and operation and maintenance. It indicates that the evaluation index system is suitable for performance evaluation of projects under construction and completed projects, and has a positive promoting role in improving implementation effect and influence of railway construction projects, and has potential popularization and application value. Read More Read Less

Abstract The total output value of the construction industry, a pillar industry of China, is continuously growing with the expansion of the production and operation scale of Chinese construction enterprises. The extensive high-input mode has promoted the economic growth of the construction industry. Despite the fruitful and amazing results, the phenomenon of production inefficiency becomes especially prominent. Though developing rapidly, China’s... The total output value of the construction industry, a pillar industry of China, is continuously growing with the expansion of the production and operation scale of Chinese construction enterprises. The extensive high-input mode has promoted the economic growth of the construction industry. Despite the fruitful and amazing results, the phenomenon of production inefficiency becomes especially prominent. Though developing rapidly, China’s construction industry possesses less ecological investments, accompanied by low environmental awareness and little importance to environmental protection, always failing to get rid of high energy consumption, high investments, and high emissions. In addition, the contradiction between the economic growth of the construction industry and ecological environment remains evident. In this paper, the production efficiency of China’s construction industry was transversely and longitudinally measured using the DEA-Malmquist index method, followed by the further analysis of the factors influencing the production efficiency of China’s construction industry based on the Tobit regression model. The results show that the average production efficiency of China’s construction industry is obviously the highest in the east, the moderate in the west, and the lowest in the center. The number of construction enterprises, per capita capital, industrial structure, the proportion of state-owned capitals, and GDP are significant at the levels of 1%, 10%, 1%, 1%, and 1%, respectively. The research results can provide theoretical reference for reasonably establishing an ecological efficiency evaluation system for the construction industry to analyze the differences in ecological efficiency among different provinces and regions, further find out the key factors influencing ecological efficiency, propose the corresponding pertinent policy suggestions, and ultimately improve the ecological efficiency of China’s construction industry. Read More Read Less

Abstract Due to the nature of underground structures, detecting defects in pile foundations is very difficult. Many methods for detecting such defects are currently in use, with various advantages and disadvantages. A new defect detection method has been proposed—thermal integrity detection. When an abnormal concrete temperature occurs, this abnormality is attributed to a defect within the concrete. When the temperature is... Due to the nature of underground structures, detecting defects in pile foundations is very difficult. Many methods for detecting such defects are currently in use, with various advantages and disadvantages. A new defect detection method has been proposed—thermal integrity detection. When an abnormal concrete temperature occurs, this abnormality is attributed to a defect within the concrete. When the temperature is elevated, it is attributed to bulging; when the temperature is depressed, it is attributed to necking, mud entrapment, or hollowing. Using finite element analysis can make the identification of defects quantifiable, but the study of concrete defects in pile foundations becomes complicated due to undesirable choice of temperature measurement point locations, reducing the efficiency and accuracy of finite element inverse analysis. Based on previous research, the location of temperature measurement points is optimized in this work. First, the effect of the change of reinforcement position on the concrete temperature field is studied, and it is confirmed that the change of reinforcement position affects only the location of the measurement points, not the concrete temperature field itself. Then measurement points on the concrete surface are selected for finite element inverse analysis of the pile temperature field and the results are compared with measurements in the field. The new measurement points can avoid irrelevant factors in the finite element inverse analysis of the pile foundation temperature field. The complexity of the finite element inverse analysis is greatly reduced, and the accuracy of defect location and size identification is improved. Read More Read Less