Advanced Materials Research Vol. 680

Abstract: The crack control of the concrete super wide box girder for New Jiujiang Changjiang River Bridge is effected by various uncertain factors such as loads, concrete strength and the release of hydration heat etc. Because of the fuzziness for the crack control of the super wide box girder, it is difficult to accurately calculate the crack width to meet with the requirement of the limiting crack design for the structure. Based on the maximal permit crack formula issued in “Concrete Design Specifications”, the fuzziness analysis is made to the crack control reliability, the index of fuzzy reliable degrees of the girder maximal permit crack width is calculated by Monte Carlo method, and the sensitivity analysis to uncertain parameters is given to provide reference of the design for River-Crossing Bridge.

Abstract: Base on the large-shaking table model test，studies on the seismic response characters of shallow tunnel in different earthquake intensity are made by mainly using numerical simulation. The results indicate that there is a good agreement between the model test and numerical simulation. the different earthquake intensity has great effects on the seismic response characters, The distribution of the lining cross-section’s internal force is oval-shaped and the value which in conjugate 45° direction is greater than crown and bottom of arch. Moreover, the internal forces vary from earthquake intensity in the same direction. It is great to recognize the seismic response characters of shallow tunnels through the study results and it provides reference for the similar projects.

Abstract: Railway track and nearby structures in the vicinity of high-speed railway are exposed to low-amplitude small-strain vibrations as high-speed railway traffic construction activities arise. These low-level dynamic events can lead to a non-linear softening behavior of the “elastic” stiffness and a considerable amount of energy dissipation in soils with a gradually increasing strain. The modelling of these non-linear behaviours are an important to predict lifetime and serviceability of existing structures in the vicinity of high-speed railway. An objective of this study is to develop validated computational models that can be used to perform stiffness and damping characteristics of saturated clayey soils due to low-amplitude small-strain vibrations. This paper provides an insight in the normalized shear modulus G/Gmax and damping ratio D in relation with shear strain amplitude γ through free-vibration column test, and proposes a modified Davidenkov model.

Abstract: The paper focuses on the research of mechanical behavior of the CFRP steel reinforced concrete filled with steel tube column under biaxial load. The authors make a simulated analysis mode with the general finite element analyze software, ABAQUS. By the way of unit selecting, meshing, contact setting, the mode is calculated by the ABAQUS/Standard which is used to analyze the mechanical behavior of the specimens. Based on comparing the load-displacement curves under different axial compression ratios, it can conclude that with the increasing of compression, the ultimate load reduces obviously. At the same time, the ductility coefficient also descended slowly. All the ductility coefficients of different specimens are all larger than 2, which meet the code very well. So the mechanical behavior of the column is very well.

Abstract: 2D numerical wave flume is established based on the VOF method and k- model to numerically simulate the interaction of wave with perforated plates. The internal source generation of wave is applied in making wave area whose end is placed the sponge layer to absorb the reflection of wave. The numerical results of reflection coefficient before perforated plate are compared with the experimental results of reference (Liu, 2008) to verify the numerical method. By changing porosity, the effect of porosity on reflection coefficient can be analyzed. Moreover, the pressure difference between the outer and inner of perforated plate was studied, and then the mutual influence of porosity on the pressure difference is obtained according to the substantive numerical results.

Abstract: Sandwich constructions with a lightweight core are more and more widely applied, which are liable to local indentation when subjected to concentrated loading. Dynamic response of sandwich constructions under low-velocity impact is predicted based on the quasi-static indentaion law in our previous study, and the equations of motion are obtained based on damping-mass models. The analytical solutions show a good agreement with numerical ones using the ABAQUS code.

Abstract: A nonlinear finite element method is used to analyze the dynamic property of a five-storey reinforced concrete (RC) frame structure with and without carbon fiber reinforced plastic (CFRP). When the frame strengthened by CFRP, seismic performance of that is improved better than the frame without CFRP. The inter-story displacement angles of the frames with and without CFRP satisfy the seismic requirements from the results of earthquake transient analyses, when the frame is exposed to the frequent and rare earthquake.

Abstract: The pattern and characteristics of seismic damage for Shuangjiangkou ECRD and Houziyan CFRD models were studied through large-scale earthquake simulation shaking table tests in this work. The test results showed that the main earthquake damage pattern of rock-fill dam is permanent residual deformation and shallow slide on the downstream slope. Seismic residual deformation of rock-fill dam, which is filled and compacted well, is very small. Regardless of ECRD or CFRD, the horizontal displacement and settlement on downstream slope are significantly larger than upstream slope under empty reservoir. The analysis of residual deformation and vibration frequency before and after failure indicated that aseismic performance of CFRD is superior to ECRD. Because of the remarkable whipping effect in the high rock-fill dam, the key parts of aseismic design is downstream slope near the dam top, where appropriate aseismic measures should be taken.

Abstract: Based on the engineering background of Shijiazhuang six-line tunnel of Jing-shi Passenger Line, field measurements and indoor model test are both used to solve the stability issues of large ultra-deep foundation. Surface subsidence, pile displacement, and the force loss of prestressed anchors are analyzed. The results show that the model test and field test is basically the same, prestressed anchor cable can control surface subsidence and horizontal displacement of the pile effectively, so as to ensure the stability of the pit.

Abstract: An experimental program under cyclic load is performed on two half-scale interior moment end-plate connections to concrete filled tubular (CFT) columns. Flat and curved stiffened extended end-plates were welded to the steel beams in the shop, and bolted on the site to the square and circular CFT column tubes respectively, using steel rods passing through the column. The experimental results demonstrated that both circular and rectangular end-plate connections showed similar performance in a ductile manner and the stiffener elements were effective to form the plastic hinges away from the welding zone, also the proposed curved end-plate connection with rods passing through the column in “X” shape was effective. The test specimens showed a plastic rotations capacity of 0.054 radian.