Advanced Materials Research Vols. 639-640

Abstract: Load distribution machannism between bents of piled wharf is an important issue.In view of the shortage of the traditional design method for piled wharf structure,this paper established the nonlinear structure-soil numerical model by finite element method software ANSYS.Based on the numerical analysis method, shear distribution coefficient of three different structure themes under high water conditions and low water conditions were Analyzed.Through post-processing process,information about the moment,shear stess of piles were obtained.The results showed that the integrity and capacity of resting horizontal load is increased by setting of longitudinal beams,.and the lower the collision position is,the more concentrate the distribution is..The conclusion and research method of this paper can be used as a reference for similar project in future.

Abstract: Semi-integral abutment fully jointless bridges, which connecting the main girder, the approach slab and the reinforced approach pavement all together and eliminating all the deck expansion joints and also the approach reinforced pavement joint is studied. As we know, the temperature variation is the key influence factor of the basic performance of the fully jointless bridges. When the temperature drops, the cracks appeared along the reinforced approach pavement. In the paper, emphasisis primarily made on simulating the temperature drops. A 28m full scale model stretching experiment simulating the temperature drops has been carried out in laboratory. After the experiment simulation we found that:(1)The crack width of approach pavement distribute uniformly at the pre-cut joints and their crack widths ranged mainly between 0.2mm and 0.8mm and the mean crack width was 0.37mm when the maximum stretch length at the end of the approach slab reached 9.87mm, which was within AASHTO and the Chinese highway pavement specification allowable value; (2)the load transfer capability coefficient at the third pre-cut joint with the maximum crack width (0.97mm) was 84%,which also satisfied the allowance of Chinese highway pavement specification. So this reinforced approach pavement is safe to connect semi-integral abutment bridge for the temperature length of 45m with the maximum temperature decrement of =20 ºС from the average reference construction temperature.

Abstract: The suspended dome structure, which is a new kind of hybrid spatial one composed of the upper single layer latticed shell and the lower cable-strut system, generally has smaller rise-to-span ratio, thus the overall stability is one of the key factors to the design of the structure. The nonlinear buckling behavior of an elliptic paraboloid suspended dome structure of span 110m80m is investigated by introducing geometric nonlinearity, initial geometric imperfection, material elastic-plasticity and half-span distribution of live loads. The study shows that the coefficient of stable bearing capacity usually is not minimal when the initial geometric imperfection configuration is taken as the first order buckling mode. The unsymmetrical loading distribution and the material nonlinearity might have significant effects on the coefficient. The structure is sensitive to the changes of initial geometric imperfection, and the consistent mode imperfection method is not fully applicable to the stability analysis of suspended dome structure.

Abstract: Composite slab by steel bar truss and concrete was a new style of floor slab. Because there were the small steel bar trusses in precast member, its short-term rigidity was higher than the normal composite floor slab. The structure was divide into four kinds, according to the relative location of the neutron-axis and the combined interface of slab; the relative value of the moment in first phase and the cracking moment of the precast slab. The different formulas to calculate short-term rigidity of precast member for four kinds were obtained. Through the models of composite slab by steel bar truss and concrete with different dimensions were established using finite element structural program, the formula feasibility was confirmed

Abstract: For the volume of the new prefabricated bridge with integral structure is huge and transportation and storage are difficult, scissors mechanism driven by hydraulic cylinder is presented to bridge design. Wth theoretical analysis, the position of the node, velocity and acceleration are analyzed. Using the ADAMS software, the whole model of deployable bridge section is established. The multi-body dynamic simulation of the whole model is studied. The simulation results are compared with those of theoretical analysis. The maximum error of them is 2.26%. The methods and conclusions are available for the design of developable bridge section.

Abstract: Retard-bonded prestressed concrete which has appeared in recent twenty years is a new and distinctive prestressed system. For the research on mechanical behavior and service property of retard-bonded prestressed concrete members, retard-bonded prestressed strands were made by manual work in this paper. Experimental research and theoretical analysis of three retard-bonded partially prestressed concrete T-beams were carried out under static loadings. The law of crack development and distribution both with the relationship between load and maximum crack width were studied in the paper. Test results were contrasted with experimental studies of two traditional partially prestressed concrete T-beams, and the characters and merits of retard-bonded partially prestressed concrete T-beams were obtained. It provides theoretical reference for the actual project application of the new retard-bonded prestressed concrete system.

Abstract: The WuSu Bridge of HeiXiaZi Island is a hybrid girder cable-stayed bridge with one pylons and single cable plane. Based on the similarity principle, a 1:3 reduced scale test model of steel-concrete joint section was designed to study the load transfer mechanism and verify the rationality. The test model was loaded according to the serviceability limit state, and the stress distribution of control sections and main members were obtained. The finite element analysis on the test model was carried out and the load transfer mechanism was studied by the way of combining the test results and the FEA results. As shown in the results, the load from steel is smoothly delivered to concrete through steel-concrete joint section, and the load distribution of the components of steel-concrete joint section is rational. It is proved that the steel-concrete composite joint section is reasonably designed.

Abstract: Simulation studies of seismic behaviour of bolt-endplate connected composite structural systems consisting of CFDST columns and steel beams frame with reinforced concrete slabs are presented in this paper. Based on fiber-section model, analytical models were developed to predict the elastic-to-plastic behaviour of the prototype frame. Analysis results indicated that the structural behaviour under the simulated seismic loadings was consistent with the expected performance objects for different earthquake hazard levels corresponding to current seismic design codes, implying that effective seismic performance of composite CFDST frame with bolted connections can be achieved. The primary analytical simulation shows the suggested bolted endplate CFDST system has the potential to offer appropriate strength and adequate stiffness for buildings located in areas of high earthquake intensity, and provides basic information for further experimental researches to validate the seismic performances of the bolted end-plate CFDST structures.

Abstract: This research focuses on mechanical performances of UHTCC-FGC beams under monotonic and fatigue loading. Three UHTCC-FGC beams are tested, including two monotonic beams and one fatigue beam. The stress level of fatigue beam is set as 0.85. The constant ratio of minimum stress to maximum stress is set to 0.2 to avoid any impact and slip between the loading machine and the specimens during testing. The specimen is subjected to sinusoidal cyclic loading at 1 frequency. During the experiments, the fatigue life, deformability and loading capacity of UHTCC-FGC beams are measured and recorded. Meanwhile，the development of cracks and the failure pattern of UHTCC-FGC beams during the test are observed at the same time.

Abstract: Forecasting the distortion of civil engineer projects need the support of mathematical statistical theories. The mathematical statistical theories have many different types, such as auto-regression and subsection-regression. The author supervises the tunnel settlement by those two theories, the result shows that: the auto-regression theory is suitable for the project safety & quality forecasting; if the project has regularity changing during distortion process, the subsection-regression theory is a very good tool when the supervision situation needs different mathematical models to describing.