Applied Mechanics and Materials Vols. 584-586

Abstract: Collapse is a common accident during underground engineering construction. Risk analysis of collapse during construction for a subway transfer station with large span and small clearance is done by using theory of risk analysis, for preventing collapse accidents during construction effectively. Considering the difficulties of construction of the station, the risk assessment system is proposed. Using Analytic Hierarchy method (AHP) to analyze the collapse risk. Then it's major risk factors and collapse risk's level is gained, and some corresponding measures are proposed.

Abstract: Unsymmetrical loading twin-arch tunnel which has its own characteristics is different from the general separated tunnel. This paper takes a unsymmetrical loading twin-arch tunnel as the background, supervises the tunnel and clears up and analyzes the monitoring data. The results shows: (1) The subsidence of arch crown grows with section excavation, it diminishes gradually and tends to be stable in the initial stage of support and the complete stage of inverted arch. (2) The convergence pre-day of tunnel surrounding rock increases and becomes stable until the lower inverted arch has finished in the effect of unsymmetrical loading and excavation. (3) The surface position of tunnel midline is the most significant position of excavation influence. (4) Unsymmetrical loading makes the lining and middle wall become dislocated, and cracks and peeling phenomenon appears. These conclusions can provide reference for slope design, construction process and site monitoring for unsymmetrical loading twin-arch tunnel under similar conditions.

Abstract: attached type lifting scaffold is a important engineering machine which is used for building construction. In this paper, two type lifting systems of the attached type lifting scaffold are studied. Using electric hoist to lift scaffold frame which is widely used in current attached type lifting scaffold can’t maintain each scaffold position moving synchronously when scaffolds are lifted by multiple hoists. The new type lifting system which uses screw transmission to lift or fall scaffold frame can avoid failure when the attached type lifting scaffold is blocked and jammed. And the control circuit of new type lifting system can indicate the overload position. Therefore, the new type lift system is safer for the construction workers.

Abstract: This article from the detection quality control measures, testing the quality assurance system, testing organization and management systems, testing technology and other aspects of the work are discussed assay impartiality and reliability.

Abstract: The sluices of the Yellow River Diversion Project in Shandong Province are mostly constructed from 1970s to 1990s. According to the regular examination records and the safety appraisal reports, the majority of these sluices are operating with risks and diseases. This paper analyses several factors in terms of design, construction and management, and proposes corresponding disposal strategies. The analysis indicates that regular examination, well maintenance and perfect control are strongly recommended; meanwhile reinforcement should be applied in sluices with risks and diseases to guarantee the operational safety.

Abstract: Based on properties of high-speed railway bridge and rail system restraints, the rail-bridge model is established by considering CRTS II unballasted track and bridge structure. The results show that the effect of CRTS II system restraints on seismic response for multi-span simply supported girder bridge is greater so the rail-bridge model should be adopted in earthquake response analysis. Due to the effect of longitudinal stiffness of the railway and bridge transitional section such as terminal spine, the more significant is unloading for seismic response of the side piers if the fewer is the number for the rear-structure spans.

Abstract:

The experiments of a five-story steel frame on shaking table verify that the slide-roof system can markedly reduce vibration. When the ground motion is strong, the vibration reduction is effective and the influence from the static friction is little. The experiments show that this slide-roof system possesses good robustness to its friction.

Abstract: A tank with large capacity and high position results in a negative impact on structural seismic resistance usually, but these tanks can be modified to act as tuned liquid dampers (TLD). A high-rise steel structure with 14 stories with this kind of tank is analyzed in this paper to introduce the action about the tank-TLD. A finite element fluid-structure interaction model is established for ABAQUS software and the effects of different parameters, and the optimal parameters about the tank-TLD are studied.

Abstract: How to identify and remove the noise of the dam monitoring data is an important work of dam safety-monitoring. The article makes use of a new compromise thresholding method to denoise the the dam horizontal displacement. Based on the de-noising data, the article uses the PSO-SVM to overfit and predict the dam horizontal displacement and compare the results with multiple regression.The result shows that the combination of the new compromise thresholding method and PSO-SVM has a better prediction accuracy.

Abstract: Due to increasing traffic on long span bridges, behavior of expansion joints is believed to be largely influenced by pounding impact from passing vehicles. In order to precisely understand behavior of expansion joint under vehicle impact loading, a new analysis scheme is proposed which incorporates interaction between vehicle and expansion joint. Mathematical model of vehicle is established and solved with Newmark method. Expansion joint is modeled with refined solid element in Finite element software ABAQUS. The analysis indicates that vehicle loading can induce large dynamic response of expansion joint in long span bridges.