Advanced Materials Research Vols. 671-674

Abstract: Damage diagnosis of civil engineering structures has become one of the hot spots of the current international research in the field of Civil Engineering.This article describes the tasks and objectives of structural damage detection in civil engineering,systematically expounded the civil engineering structural damage diagnosis describes the traditional methods of structural damage diagnosis, static methods and dynamic methods, and evaluated their respective advantages and disadvantages.Finally, the study made several suggestions and Prospects for structural damage detection.

Abstract: Distress in mass concrete is a problem in highway and bridge engineering. These mass concrete structures craze not by external loads, the temperature variation caused by heat of hydration and the temperature stress caused by concrete shrinkage are the main causes () for the leaks [1]. Therefore, the thermal stress and the temperature control have significant meaning in the mass concrete structures. Thermal cracks will break the structure globality and also decrease the durability of the structures during the construction time. In addition, the temperature variation will have a remarkable affection on the stresses variation of the structures during the service time [2]. This paper will discuss the temperature monitoring and the crack control projects of the mass concrete based on the cushion cap of an extradosed cable-stayed bridge which is being constructed.

Abstract: In this study, whether the ultra-long basement structure that have been designed and constructed in recent years generate harmful cracks or not was investigated. The crack prevention technologies applied in the ultra-long basement concrete structure of 62 constructed projects in Shenyang city, China was analyzed. The results show that the harmful cracks in ultra-long basement concrete structure can be avoided by taking effective measures such as: strengthening the reinforcement of structure weakness , setting post-pouring belt of concrete construction , expansion reinforcing band, and using anti-cracking waterproof agent etc. Thereby, the hidden danger in structure is eliminated, and the safety of structure is ensured.

Abstract: In structural health monitoring system, data analysis is one of the most important parts. It is mainly for processing and analysis of the collected data, among of which, the correlation analysis of the collected data can be used to verify the feasibility of the system. This paper applies the method of wavelet de-noising analysis to reduce signal noise and utilizes MATLAB and LabVIEW to calculate the cross-correlation coefficient in simulation statistics independently. To verify the feasibility of correlation analysis method and the data processing, simulation study is finished based on sampled data, which are the information of measuring points of strain and temperature from the Baishazhou Bridge. The cross-correlation coefficients between various signals can provide the reference to the whole health status of the civil engineering structure, and then enhance the accuracy of structural health assessment.

Abstract: The gray system theory modified by Kalman filtering method is used in the inconsistent between the observed and theoretical values of the segment’s deflection in bridge cantilever construction process. Firstly, get the statistically optimal estimatations of the observed value using Kalman filtering theory, then making it as the initial value, the gray system theory is used to predict the deflection of the next segment, and the formwork elevation of next stage is fixed. As a project example, a prestressed continuous girder bridge in Zhongshan City, Guangdong Province is put forward, respectively using the gray system theory and the gray system theory modified by Kalman filtering method to predict the deflection. According to the comparison from above two methods as well as the closure precision, the conclusion is the gray system theory modified by Kalman filtering can be more effective to reduce the deviation of observed and theoretical values, that means a better bridge linear control.

Abstract: With the application of Global Positioning System (GPS) echnology using in the field of modern transport, more and more long-span bridges have set up the GPS system to monitor the real-time deformation in safety monitoring system. Nowadays the highest measuring accuracy of GPS technology achieves millimeter, and the sampling frequency can reach 20Hz. It can solve real-time deformation data and adapt to the complexity and poor working environment. Based on the application of GPS technology using in long-span bridges safety monitoring system, this paper set the Huangpu bridge as the engineering project and demonstrate how to apple the GPS technology in deformation monitoring and security evaluation.

Abstract: The Cuplok steel tubular scaffoldings (referred to as: CSTS) are large-scale temporary facilities in bridge construction. Recent years many collapse accidents cause people to think about the safety issue of scaffoldings. The content of safety monitoring of CSCT is put forward. On the base of bridge construction monitoring, the monitoring and control procedures and methods of CSTS is descripted in detail. An instant shows that the safety monitoring can effectively ensure the safety of the CSTS in construction.

Abstract: Stress monitor and control in Cantilever Construction of a big span bridge is introduced. Influences of load state, temperature and humidity are eliminated through structure testing and parameter identification during construction. The errors between measured data and design values are analyzed to ensure construction to agree with the design.

Abstract: Landslides, as a natural phenomenon, cause a large number of casualties and property losses every year, and serious problems of people's production and living, therefore,real-time monitoring of the landslide is very important.Combination landslide uncertainty, unexpected and hidden characteristics, we need to introduce a new technology to realize the all-weather monitoring of landslide strip. Therefore, this article will focus on the introduction of GPRS technology of landslide geological disaster monitoring and landslide real-time monitoring system based on GPRS technology.

Abstract: Based on the analysis of regional geology and hydrogeological conditions of Wannian mine of Fengfeng coalfield, according to field's borehole data, geological data and hydrogeological data, we use GMS software to make the three-dimensional visualization strata modeling in Wannian mine of Fengfeng coalfield. Through cutting geological model built in different directions or at different levels and rotating to different directions and different angles, the complex underground geological environment is displayed in three-dimension, which helps geologists to analyze the geological conditions and solve various geological problems.