Applied Mechanics and Materials Vols. 71-78

Abstract: Take a typical cross-section of rockfill embankment slope in Yaan-Luku highway as the research object, reliability analysis is studied under the condition of water table of 840.85m, 851.50m, and loading condition of natural state and horizontal seismic acceleration of 0.2g, respectively. Raw data use Kolmogorov-Smirnov test (K-S test) to determine the distribution type of parametric variation. And the parameters were sampling with Latin hypercube sampling (LHS) method and Monte Carlo (MC) method, respectively, to obtain state function and determine safety factors and reliability indexes. A conclusion is drawn that the times of simulation based on LHS method were less than Monte Carlo method. Also the convergence of failure probability is better than the Monte Carlo method. The safety factor is greater than one and the failure probability has reached to 35.45% in condition of earthquake, which indicating that the instability of rockfill embankment slope is still possible.

Abstract: Large quantities of mined ore materials are processed annually to obtain the various types of minerals that are essential to industrial processes. At the same time, a lot of tailings held up by tailings dam. Due to its execution simplicity and low cost, upstream tailings disposal has been the most common method used for the surface disposal of tailings produced from processing the mined ore materials. The phreatic surface is higher for upstream-type and loose saturated deposits may be incorporated in mostly zones, so that upstream dams are particularly susceptible to liquefaction and flow slide damage under earthquake. Earthquake disasters of tailings dam are analyzed, the mechanism of flow induced by seismic liquefaction are preliminarily studied, and the flow slide models are researched from four aspects of foundation damage, initial dam damage, sub-dam damage and inner slope sliding damage. It is of great significance to guide the antiseismic design of tailings dam and improve the level of safety management and reduce the mine disaster losses.

Abstract: A backfill clay method which is often adopted in small earth dam’ anti-seepage and reinforcement engineering has been introduced, and its using experiences in Zhejiang province, east of china, has been summarized. The design and construction process using the method has both been represented in the paper, with several technical difficulties had been selectively discussed. Application in hundreds of dams during the past decade showed that the method is characteristic of short working term, low cost, no need of many oversize machine, simple working technology and convenient application.

Abstract: Drilling bored piles foundation has been built in the dam and reservoir because of the highway bridge across the dam. Considering the bridge built, the horizontal and vertical force will be passed and act on the dam base. Based on Bishop method, the stability of the dam was analyzed and results showed that the dam can not satisfied with the slope stability requirements. Therefore, concrete measures for reinforced were put forward in order to remove dangers and reinforce the dam.

Abstract: An important issue our engineers and technicians met is that how to do safe identification and earthquake resistant strengthening of the primary and secondary school buildings after WenChuan earthquake. The paper reviewed entirely the quality detection, identification and strengthening design of the primary and secondary school buildings in Xi'an. In this paper, the influences of the construction progress, complexity and construction period are all taken into account in order to choose the corresponding seismic strengthening method which are based on the seismic qualification and on-the-spot survey. Problems existed in project design are presented in this paper, which can be taken for example on similar engineering.

Abstract: Taking Tianjin Yonghe bridge for example, the finite element method is adopted to simulate each stages of cable replacement process, the dates of tension, the alignment of main beam and the change of stress before and after cable replacement are compared and analysed, The measured value is greatly consistent with calculated value, Stress state of the bridge has been greatly improved, the weight of main beam bearing by the cable will be shared by a few closed cable after unloading, so the cables which are more serious corroded should be replaced.

Abstract: Aiming at the upgrading project of the structural health monitoring system of Jiangyin Bridge, the moving specialty parameters such as the vertical displacement, corner joints, and the synchronization of the two sides of the bridge expansion joint are monitored and acquired by the means of the long real-time health monitoring technology. Based on a large number of measured data, the temperature-dependent regression equation between the movements and the structure temperatures of the bridge expansion joint is established, which could provide much quantitative support and scientific guidance for the daily management and maintenance of the expansion joints.

Abstract: Cracks on the Joint Part between Pier and Girder, namely Block NO.0 in the construction process, has become one of the major diseases of continuous rigid-frame bridges. Based on the real construction technology, process and environment of Yuquanxi Bridge, the uneven distribution of stress caused by various factors is precisely analyzed by ANSYS. The shrinkage difference of concrete, the excessive hydration heat, and the sunshine temperature difference is accurately simulated respectively. By comparing the numerical results with actual cracks condition, the results prove that the theoretical analyse is accord with the actual situation, and the real reason of cracks on Block No.0 of Yuquanxi Bridge is uncovered. This study is of great practical value in preventing cracks and improving bridge construction technology.

Abstract: This paper choices eleven evaluation index to establish fuzzy hierarchy evaluation index system of urban road intersection based on basic facilities, operation conditions and environment level of intersection. Comprehensive evaluation modal of urban road intersection is established by calculating relative weight of every layer through applying to triangular fuzzy function. Ten intersections obtain comprehensive evaluation based on the modal established. These intersections have been clustered three clusters by K-Means Cluster method finally. It is help to manage and control the similar intersections according to cluster result.

Abstract: As the development of the economic of China and the acceleration of urbanization, metropolises have run out of land resources. Therefore, developing and utilizing the underground space becomes the inevitable trend of sustainable urban development. The modern urban space is a three-dimensional space system which is made up of above and below parts of the space. According to the city on or under the ground, the different characteristics exist. Arranging their own appropriate functions, and avoid weaknesses, will not only make best use of their function, but also promote each to form a good system of urban functions to ensure the city’s efficient and orderly operation.