Advanced Materials Research Vols. 368-373

Abstract: Based on the calculation method by Frangopol on redundancy, the paper calculates the ultimate load-bearing capacities of a single-layer three-way grid cylindrical shell when it loses each lattice at first by a whole-process analysis program developed with double non-linear condition considered, then sensitivity analysis is done and sensitivity distribution diagram is set up. To reduce the probability of progressive collapse, it is necessary to strengthen member of low redundancy.

Abstract: Quota for the construction of enterprise management an increasingly important role, so their problems through the analysis made clear the principles of its preparation and improvement of measures.

Abstract: Excavation displacement monitoring is a kind of important measure assuring construction safety of large-scale excavation engineering.How to predict displacement accurately and efficiently in construction period using limited displacement date has become a research hotspots. Spatial threshold regression model thinking time factor has been build up according change of excavation depth and monitoring time in paper.Predicted value of deep maximal horizontal displacement using the model abolve is very close to monitoring value.Maximal average error is about 12.46% in early days and tend to 5% in later stage.It is a effective predicted method for soil deep maximal horizontal displacement in excavation engineering.

Abstract: Accidents, such as storm surge, typhoon, non-normal impacting and other abnormal operating conditions will all cause damage to the structure of piled wharf. To improve the bearing capacity of structure and extend service life, it is need to detect, evaluate and reinforce the piled wharf. This paper analyzes different reasons and ways of destruction then puts up some detection methods for piled wharf’s different components. The evaluation procedures and steps of piled wharf are also disused and mechanism of various reinforcement methods are researched in the same time. The results of this study can provide reference for the detection, assessment and reinforcement of piled wharf structures.

Abstract: Though engineering compares and numerical analysis, the analysis of construction risk control project for shaft close to current iron tower is carried on, which relies on the engineering of electric cable sending-out of 110kv transformer substation in XiGuan Intersections, the city of LanZhou (the section of underground excavation in the west of LeiTan river).The result shows that the method of isolated steel pipe and grouting technique applied for stratum consolidation can effectively control the iron tower’s deformation and decrease the construction risk.

Abstract: Steel cofferdam has an abroad application in high pile cap construction in deep water foundations. Because of the obvious three-dimensional effect and its complex stress and strain, the traditional simplified calculating method couldn’t reach the requirements of practical engineering. The general purpose finite element software Ansys was used to analyze the stress and strain of steel cofferdam and sealing concrete, and achieved a good effect to ensure the engineering safety.

Abstract: This paper presented an approach of decoupling the system represented by a time series of dam monitoring data into a series of subsystems and modeling these subsystems with non-linear models. The decoupling analysis of original system was achieved using wavelet packet energy spectrum (WPES). The non-linear models used here is augmented mixed regression (AMR) model. Some detail problems such as how to find the scale for fine wavelet packets, the modeling of sub system, how to choose a forecast model and the data de-noising were studied in this paper. Through the analysis on the monitoring data of a roller compacted concrete (RCC) gravity dam, it proved the good performance of this model in data prediction.

Abstract: Displacement is a very important parameter in the civil engineering safety evaluation. But traditional displacement measurement methods are impractical and inconvenient in application, for the reason of money cost, time invested or labour involve. Spline-method is proposed to describe the displacement curve based on the angle values measured by inclinometers. Cubic spline is chosen for figuring out the inclination function and displacement values all over the structural. Numerical experiments have proved that Spline-method is feasible and has very high precision.

Abstract: In order to verify the role of fiber bragg grating strain gauge in strain measurement of concrete bridge, and the influence of concrete and steel strain properties by fatigue loading, the relevant experimental researches were carried out. The results indicated that the Fiber Bragg grating strain gauge could reflect the strain regularity of concrete and steel well; for the fiber grating strain rosettes inside the concrete, the pasting equipments of fiber gratings had a certain impact of the measurement effect. The fatigue loading had a certain impact of the properties of concrete and steel, in conditions of the same number of fatigue, the greater the stress amplitude the more obvious the effects. The results analysis shown that, fiber grating strain measurement innovated the means and methods of strain measurement in detailed structure of the concrete bridge, for the strain measurements of concrete bridge under fatigue loading, the FBG could still play very good effect.

Abstract: The rule of stiffness and deflection change of reinforced concrete two-way slabs strengthened by CFRP was discussed after test research. The results were analyzed with ANSYS finite element software and compared with test results, and the ANSYS finite element analysis results agreed well with test results. It shows that CFRP can improve the flexural stiffness of reinforced concrete two-way slabs and effectively restrain deflection deformation of them. So ANSYS analysis results can provide reference for the test and engineering.