Advanced Materials Research Vols. 838-841

Abstract: This paper analyses the problem of locking value of anchor cable of pile anchor supporting of a deep foundation pit in the north of Kunming city. There are many influencing factors of locking value of anchor cable such as relaxation loss of anchor cable materials, tensioning system, pre-stress loss caused by anchorage friction, geological conditions and so on. And the author put forward the corresponding treatment measures for achieving the stability of supporting structure.

Abstract: With the growth of the national economy, the social demand for coal resources is increasing. In order to maintain the sustainable development of the national economy, we must develop the deeper and wider coal layers. In deep mine construction and in the process of extending shaft downwards, we often encountered with soft rock zones and rock fracture zones where were often subjected to floods. Grouting technology is one of the most effective and reliable method to deal with water in the mine. But the traditional grouting method could not reach the good effect in plugging water. According to the local engineering practices and experiences, the new method we have mentioned above takes better effect in dealing with the problem of water permeation in ventilating shaft of Niaoshan coal mine.

Abstract: Before the construction of the deep pit foundation, we must choose a project. Although there aren't many projects to be chosen as usual, we often feel that it's a very complex and hard work. Actually there is no a mature and general model to use. In this paper, the author attempted to use the theory of fuzzy math to establish a former to select the best project, meanwhile provided two ways to solve how to quantify the qualitative targets and how to determine the weights of the targets. Finally they were confirmed to be useful and successful by a practical engineering application. It is worthily to popularize these scientific methods in construction and management in deep foundation pits.

Abstract: The analysis to the staged construction of the long span steel transfer truss was performed. The focus was on the stress and deformation analysis of the transfer truss, the interactions of the transfer member with the concrete tube, and the combination analysis of the steel girder and concrete beam. It was proved that the method of staged construction can get the good result that can make full use of the characteristic of the steel material, make steel truss bear more load effect in the construction stage. So the load to the concrete tube is lessened, which makes the load effect of the structure is more rational. Some advices for the construction and design of steel transfer truss is also provided. Keywords:Steel truss; Transfer story; Staged Construction.

Abstract: This article used ABAQUS finite element analysis software to established the high-formwork, analyzed effect on stability of the different height formwork by contrasting lateral displacement of various heights, discussed influence of concrete pouring sequence on stability of different height high-formwork support system in the construction process. From the simulated result, it can be seen that with the increase of height, the lateral displacement increased gradually when poured in dissymmetrical way, but the stability of high-formwork decreased, the result also provides evidence for code revision.

Abstract: The structural behavior of incrementally launched bridges in the construction stages depends on different parameters. Internal force of main girder is influenced by the dead load and stiffness of main girder, the length and stiffness of launching nose. Parametric analysis on the effect of internal force of an 8×60m-span concrete continuous box girder bridge was carried out. The results show that bending moment increases following the increase of weight and stiffness of corresponding segment of main girder. The phenomenon is even more obvious in the negative bending moment region of main girder segment nearby the launching nose. The bending moment of main girder reduces significantly when the stiffness ratio among launching nose and main girder is less than 0.15. While, the negative bending moment of main girder reduces significantly when the length ratio among launching nose and main span is more than 0.58.

Abstract: China's current economic development in the construction of large-scale historical stage, the construction industry as its pillar industries, construction tasks undertaken increasingly diverse, employing industry has become China's largest labor groups, their health, safety and environmental issues is even more affected by our state and society. However, as more and more construction projects, process more complex, especially from the last three years the national production safety situation analysis of construction reports, building construction project safety, health and environmental issues have become increasingly prominent, reduce or avoid course of construction, security incidents, quality accidents and protecting the safety of employees, health is present in the construction sector and the need to effectively address the main problem.

Abstract: Of the construction processes involved in high-rise building construction, core wall construction is a highly repetitive construction works. Therefore, the effective management of core wall construction works by a project manager can save costs and shorten the duration of high-rise building construction. This study analyzes a case in which a core structure succeeding method (CSSM) is applied to core wall construction. The results of the case study found that the efficiency of CSSM in terms of construction costs and duration is higher than that of the core wall preceding construction method (CWPCM).

Abstract: In this paper, a new comprehensive assessment method of pile construction quality based on analytic hierarchy process is proposed considering that the current specification is uncertain about quality assessment. This method establishes the comprehensive assessment index system of pile construction quality taking account of the influence of the pile velocity, pile length, geological condition, bridge importance level, pile defects and other parameters on pile construction quality assessment. It constructs pile construction quality assessment model through determining the weight of each index based on analytic hierarchy process to improve the evaluation method of pile construction quality. The good results achieved in practical engineering demonstrate that the proposed method possesses favorable accuracy.

Abstract: The artificial neural network is used to solve the reliability analysis of the engineering structure. When the limit state function of structure is highly complex or with nonlinearity, it is time-consuming or cumbersome to carry out reliability analysis with traditional methods. The artificial neural network response surface method is adopted to analyze the fatigue reliability of loader boom, the working process of loader machine is analyzed with FEM software and analytical method, the stress-time history and strain-time history of loader boom are schematized with rain-flow algorithm, consequently the fatigue life analysis on the structure can be carried out with local stress-strain method. The artificial neural network method is used to fit the performance function as well as its derivatives, so as to calculate the reliability of the structure. The numerical example results show that the proposed method has capability of solving industrial-scale reliability problems.