Advanced Materials Research Vol. 859

Abstract: Hollow rectangular reinforced concrete piers have been widely used in tall-column and long-span bridges. Two large-scale experimental models of the hollow reinforced concrete bridge piers were built to study the seismic performance of the piers subjected to biaxial bending under constant axial load. The objective is to evaluate seismic performances of the model piers and the factors affecting the seismic performance of the model piers by comparing their failure mechanism, bearing capacity, ductility, energy dissipation capacity, etc. The results show that the hollow rectangular specimen experienced flexural failure with plastic hinges formed at the bottom of the piers when subjected to combined axial load and biaxial bending. The bearing capacity of the specimen increases greatly and the ductility decrease insignificantly as the axial compression ratio increases from 0.1 to 0.2, while the energy dissipation capacity is increased by 121.8%, however, the absolute value of total cumulative hysteretic energy is not magnificent.

Abstract: In allusion to double sheet piles(DSP) global optimal solution, the response surface(RS) technique based on Uniform Design- Support Vector Machine(UD-SVM) was introduced to build the RS by nonparametric regression, thus to avoid the complex non-linear RS form between the double sheet piles parameters and indexes under the current standard. Use the Monte Carlo simulation as generator to produce samples, the RS can do considerable and non-repetitive efficiency prediction and get global optimal value satisfying to the target value with high accuracy and stability, also without figuring out the explicit formulations. This article applied the method to a double sheet piles optimal design, and took minimum engineering quantity as criterion to screen for the optimal parameters aiming at illustrating the feasibility.

Abstract: This paper reports a finite element analysis of the flexural behaviour of concrete-filled steel tubular members with elliptical section. A set of test data were used to verify the FE modeling. generally, good agreement was achieved. Typical curves of moment (M) versus deflection at mid-span (u_m), as well as stress distributions of steel tube and concrete of the composite members were compared and discussed. The results clearly show that the FE model is available for predicting the load-bearing capacities and the failure modes of the specimens.

Abstract: The weak interfacial bond strength EPS beads and large intercommunicating pores in the EPS lightweight concrete result in degradation of the mechanical properties of the concrete. The interface bond properties between EPS beads and the concrete can be improved by using the polyvinyl acetate (PVA) emulsion and silica fume. To prevent EPS beads rise up to the surface in the concrete mixing and reduce the number of larger pores in the concrete, vibrating with pressure, which can enhance the mechanical properties of the concrete, is applied. To decrease the aperture size of large pores and enhance thermal performance of the concrete, it is appropriate to decrease EPS beads size . The three-dimensional net structure formed by the polyvinyl acetate (PVA) emulsion and the hydration products of cement in the large pores of the concrete can reduce connectivity of the pores in the concrete ,thus the anti-frozen properties of the concrete is up as well.

Abstract: This paper describes the use of measured values in the probabilistic tasks by means of the new method which is under development now - Direct Optimized Probabilistic Calculation (DOProC). This method has been used to solve a number of probabilistic tasks. DOProC has been applied in ProbCalc a part of this software is a module for entering and assessing the measured data. The software can read values saved in a text file and can create histograms with non-parametric (empirical) distribution of the probabilities. In case of the parametric distribution, it is possible to make selection from among 24 defined types and specify the best choice, using the coefficient of determination. This approach has been used, for instance, for modelling and experimental validation of reliability of an additionally prestressed masonry construction.

Abstract: To find out the connection of screw joints and base materials or the metal crest surface at the head of screw which is destroyed first, the tensile bearing capacity of joints between self-drilling screws (SDS) and the base materials were tested first. With two types of SDS joints furnished with C-saddle washers (C-SW) and M-saddle washers (M-SW) respectively, test and analysis on the tensile bearing capacity of SDS joints were undertaken. Corresponding finite element (FE) models were analyzed by ANSYS/LS-DYNA software. Based on mechanical analysis, a new theoretically computational formula for tensile bearing capacity of SDS joints is proposed.

Abstract: The longitudinal axis of the bridge is not perpendicular to the flow of the river and the road, skew bridges are usually used, whats more, the Stress is very complicated. Through a skew bridge static and dynamic load test, the bridges stress was analyzed, in the same way, deflection and dynamic characteristics could be analyzed. The most important was the safety performance of the bridge could be evaluated.

Abstract: The measurement accuracy of the cable tensions in the hanger rods of concrete filled steel tube arch bridges is important for the correct evaluation of bridges condition. Based on Jinpan Bridge-a half through concrete filled steel tube arch bridge with 80 m span in Tiantai, it was put forward the vibration frequency method for testing and evaluate suspender tensions with the help of analysis vibration characters of the suspender. The precision of cable force calculation formula was verified after comparing the practical tension with the designed tension obtained from tension jack method. Then, according to the test results and values predicted by the presented cable force calculation formula, the cable tensions were adjusted. Cable tension test results in the finished bridge show that this method is feasible.

Abstract: In order to study the load property of variable cross-section continuous box girder bridge, in this paper, the static and dynamic load test were carried on the main span for Xiaoqinghe super-large bridge in Shandong province. The main girder stress, deflection, impact coefficient, self-vibration frequency and the static and dynamic characteristics were analyzed, compared with the theoretical calculation to judge the safety of the bridge.

Abstract: This paper briefly described borehole wave velocity test and the principle and method of wave velocity test technique, by using acoustic measurement and control technology of tunnel rock mass test, integrality index of rock mass is obtained, ultimately, we evaluate the rock mass integrity. The actual application effect is good and provides an important basis for the engineering rock mass quality evaluation.