Advanced Materials Research Vols. 250-253

Abstract: A developed light wall composed of oriented structural straw board (OSSB) and tennon-and-mortise connection wood frame (TMCWF) was introduced. The wall build-up with the wall-modular, top plate and sill plate, the wood frame members of a modular are connected with tennon-and-mortise, and the panel is OSSB. The seismic behavior of the light wall modular composed of OSSB and TMCWF was tested under low-cyclic loading based on seven modular-wall specimens, which have various spaces of vertical frame members, panel type, panel thickness, space of nails and vertical loads. The performances of the specimens such as the failure models, hysteretic curves, shear capacity and ductility are obtained. Experimental results show that the final failure is induced chiefly by penetrating the panels for nails; the hysteretic curves are typically reversed S-shaped; the type of panel, the thickness of panel, the space of panel nails are the major factors to influence the shear strength of the modular-wall; the rigidity is big at the initial stage and then reduced sharply; the displacement ductility factors of the wall-modular calculated with specification method are low.

Abstract: This paper dealt with the influence of the steel-concrete interface quality and environmental conditions on reinforcement corrosion. High size concrete members were cast to get different interface quality decreased with the height of rebar due to the top-bar effect. Five groups of specimen with two concrete covers have subjected to different exposed programs. The experimental results showed that the concrete cover significantly influenced corrosion initiation and corrosion rate by blocking the penetration of aggressive agents. The height of rebar affected the corrosion initiation because of the variation of concrete porosity, interface defects and chloride threshold. The existence of defects at the interface was more important than the size of defect for corrosion initiation.

Abstract: It is a very effective technology methods that using dynamic numerical simulation of discrete element method to study the large deformation problems of underground engineering rock mass which in the complex rock mass mechanics environmental conditions.Research achievements show that the development of deformation failure of the tunnel surrounding rock and the final convergence stability are mainly controlled by rock mass structure and its stress environment in the special toppling deformation rock mass. Deformation of the rock mass that in the lateral unloading and relaxation and also has a complex rock mass structure developed sustainably and progressivity over time,will eventually seriously damaged in roof fall. The surrounding rock deformation of the tunnel ,which have a good rock mass integrity and do not have the obvious unloading and relaxation stress environment, gradually tended to be stable after the initial deceleration-type development.

Abstract: This paper describes the influence of raw material, water-cement ratio, sand ratio, cement-sand ratio and fly ash content on impermeability of waterproof concrete. The value ranges of several important mix parameters are summarized, that provides the reference to select the parameters of mix proportion of waterproof concrete for subway.

Abstract: The geotechnical test can't be applied to sand as the original sample is difficulty to collected by drilling, so the cohesive strength C of sand can't be acquired in geotechnical test. Generally speaking, according to the Mohr–Coulomb law, C=0. From the numerical point of view, when the slope angle is greater than the internal friction angle, the global stability of slop can’t meet the requirements of standard. However, that’s not the case in fact. In practice, the slope angle can be determined by means of analogy. Although successful experiences have obtained, there still exist some potential hazards. In this paper, we have made some studies on the cohesive strength of sand based on the control of instability of a deep foundation in Xiang'an District, Xiamen, China.

Abstract: In this paper, a differential segment of curved beam in the vibration state is analyzed, and the internal force equilibrium equations are established, then the vibration differential equations of curved beam are derived by considering Timoshenko’s geometric equations and physical equations. The vibration differential equations derived are similar to the Vlasov’s static differential equation of curved beam. By analyzing the vibration differential equations, some characteristics of vibration are obtained, and ideas of solving the vibration differential equations are also proposed. The vibration differential equations of curved beam can be reduced to those of corresponding straight beams, validating the derived vibration differential equation of curved beam.

Abstract: Since construction drainage will inevitably cause ground settlement, it is necessary that a system optimization model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by draining and dynamic water levels during different working procedures being constraints, and the design parameter of pumping (injection) wells being the variable. The system optimization model solved the problem of which Taizhou bridge south anchor caisson foundation construction drainage induced settlement, so as to lower the damage of surrounding buildings. So the system optimization model provides a new method for active control over settlement during draining. Such a method of drainage based on system optimization model should be of significance for similar projects involving drainage.

Abstract: In this present paper a new yield criterion called M-D criterion is established based on the average of Mohr-Coulomb and Drucker-Prager criterion. The new M-D criterion is integrated with a revised FLAC^3D method for mechanical analysis. Comparisons between the results of M-D, Mohr-Coulomb and Drucker-Prager are made by cases study. The study shows that results of M-D criterion are basically between the results of Mohr-Coulomb and Drucker-Prager and have the feature of being medial in quantity.

Abstract: After the construction of building foundation with high groundwater table was finished, stopping dewatering of pit could create some effect on the force of foundation. In this paper, equivalent temperature-changed method was brought forward to simulate the influence of stopping dewatering which could conveniently use current structural analysis program to simulate the change of pore water pressure in soil. And based on ANSYS program, this method was applied in the project of Telecom Network Management Center in Shaanxi Province. Numerical results indicate that the effect of stopping dewatering on pile-raft system is significant, and some ‘abnormal phenomenon’ in In-Situ Testing is reasonably explained.

Abstract: Gravity abutment widely uses for substructure part of the bridge structure. For many reasons, there are many damages take place in the parts of abutment. The objective of this study is to evaluate the strengthening effects on the performance of highly structure of Gravity abutment. ANSYS ver.10 software is used in the theoretical analysis of capacity of abutment structure .There are two experimental models. The first model uses one ring of carbon fiber sheet and the second uses two rings of carbon fiber sheet .The results of theoretical analysis show that there are good effects when using carbon fiber sheet strengthening method.