Advanced Materials Research Vols. 838-841

Abstract: In order to explore the influence law of the uneven covering layer foundation on lock chamber structure, used the large-scale finite element software called ANSYS, chosen the first hub lock chamber on Guxue Hydroelectric Power Station which was under construction as research object, constructed a lock chamber model which had thickness variations of covering layer along the dam axis direction, calculated the results of displacement and stress distribution on lock chamber, the analysis showed that; the uneven covering layer only has impact on the displacement along thickness variation and vertical direction of the lock chamber, the affecting factor of the stress distribution on lock chamber is the size of the corresponding covering layer gap under the floor; the lock chamber deformation amount meets the operational requirements, the reinforcement on the floor of number (3) lock chamber should be strengthened, to meet structural stability requirements, it only need to have the minimum reinforcement rate reinforcement for the other two lock chamber floor and all the gate piers.

Abstract: To improve the mechanical behavior of T-shaped concrete-filled steel tubular (T-CFT) column, the method that setting binding bars along the height of steel tube is proposed. Five T-CFT stub columns with binding bars and another two without binding bars subjected to axial compression were tested. The influences of the spacing and diameter of binding bars on the failure modes, maximum strength, and ductility of T-CFT stub columns are investigated. The experimental results demonstrate that by setting binding bars or decreasing the spacing of binding bars, the buckling modes of the steel plates are changed, the local buckling of the steel plates is postponed, and the confinement effects on the core concrete can be improved significantly. By setting binding bars, the bearing capacity and ductility of the columns are enhanced by 1.17 and 3.38 times at most, respectively. By increasing the diameter of binding bars, the ductility of the columns is improved, but the bearing capacity and buckling strength cannot be improved when the diameter is large enough.

Abstract: This study examines the effect of different variables of Profiled Steel Sheet (PSS) on various aspects of Profiled Steel Sheet Dry Board (PSSDB) system. PSS is an important component of PSSDB. The sensitivity of PSS variables at the 70% to 140% of Peva45 dimensions, the profiled steel sheet at local markets, to the cross-sectional area of PSS, the ultimate load carrying capacity, and the flexural stiffness of the PSSDB system is analysed. Results are shown in charts, and the most effective variables are determined. The dominant variables are found by saving computational time in the optimization of PSS in the PSSDB system.

Abstract: In this investigation, it was planned to study the flexural and plastic hinge behaviour of reinforced concrete beams confined with GFRP wraps and polyolefin fiber addition in critical regions (plastic hinge zone) along with stirrup confinement. The variables are the number of layers and chopped/woven type of wrapping, which controls the behaviour of the GFRP, and the percentage of polyolefin addition. The programme consisted of casting and testing 20 rectangular reinforced concrete beams of the size of 150 mm × 230 mm × 2000 mm, under a symmetrical two point loading. During the casting of the beams, the middle one third 600mm of the beams were cast with polyolefin fibers concrete, of volume fractions 0.3%, 0.5%,0.7%,0.9% and 1.2%. After the curing of the beams, glass fiber mats along with polyester resin were wrapped over the beams in the plastic hinge zone (critical zone) for 600 mm length; i.e., 300 mm from the centre on each side. Polyolefin fiber addition to the lateral tie and GFRP confined beams has the advantage over the confinement by the lateral ties and FRP wrap in improving the performance under large deformations.

Abstract: Some foundation structures can be loaded with horizontal stress, for example pre-stressed foundation structures or structures on undermining areas. Then it is necessary to solute their effects, because they can have very significant effect on the building. When it is spoken about the foundation structures which are loaded with horizontal stress then it is spoken about two possibilities of this loading. In the first case there are horizontal deformations in the structure and in the second case these deformations can arise in the subsoil. In both of them it can be used the method with using sliding joint to increase of shear stress between foundation structure and subsoil. Asphalt belt is often used to create this sliding joint. At the faculty of Civil Engineering some materials are tested to better knowledge of asphalt belts properties and to more precise design and calculation of sliding joint.

Abstract: Based on the fire tests of WILLIAMS double-poles structure, considering the dual nonlinear interaction of material and geometric, established one complete finite element model of grid structure. For the performance that the physical and mechanics properties of steel will degrade while the temperature arising, simulate the test models with ANSYS, get a better numerical results, proof the numerical method is feasible.

Abstract: To Wudang Yuzhen palace gate lifting project as an example, it introduces a new type of lifting counterforce supporting system design. This lifting counterforce supporting system is designed in this paper in three aspects: the selection of lifting counterforce supporting system, steel pad, section steel reinforced concrete structure, and it puts forward the relevant suggestions: It is better to use H-steel reinforced concrete support system in building large high jacking works; In the design process of the steel cross section, it is need to focus on the bending strength and stability factors in the case of considering the eccentric force; In the design process of steel reinforced concrete walls, it is need to focus on resistance to overturning stability factor.

Abstract: In order to ensure construction safety of tunnel entrance under complicated geological condition, surrounding rock should be pre-supported. Forepoling bolt pre-supporting has been adopted in the paper and three-dimensional finite numerical simulation has been used to analyze its effect. Calculation results show that vault displacement is less than 50mm, displacement of side wall is no more than 45mm and the final safety factor fo primary support is about 5.0. So forepoling bolt pre-supporting could ensure safety of supporting structure at tunnel entrance. Meanwhile, maximum axial force of forepoling bolt is higher than 13kN appreciably. And axial force along the bolt shows step-like. Maximum is located in middle of forepoling bolt and it derecases to two ends gradually. Alao axial force of forepoling bolt in vault is larger than side wall. These conclusions coulde provide theoretical basis for safety construction of tunnel entrance.

Abstract: This paper, based on the calculation model of vertical elastic grade beam, puts forward transfer Matrix method model for calculation of sheet pile. Through setting virtual elastic support and calculating elasticity coefficient, sheet pile structure is applied to transfer Matrix method. According to the boundary conditions of sheet pile, establishing formulas to solve the initial vector , and getting the sheet pile arbitrary state vector . Using this method for a underground continuous wall structure to calculate, The results with the finite element method results come very close.

Abstract: Mega steel frame-prestressed composite bracing structure is a new kind of mega structure with a rigid-flexible composite bracing system composed of rigid Λ-shape steel brace and inverted Λ-shape flexible cable set up in the mega steel frame. By establishing the three-dimensional finite element model and considering the material and geometric nonlinearity, this paper analyzed the structural performance under whole process of static loading. The results indicate that the lateral deformation is mainly determined by horizontal load and the corresponding lateral deformation curve is bending type on the whole, whereas the deflection of mega beam is mainly governed by vertical load and pretension of cables.