Advanced Materials Research Vols. 838-841

Abstract: Considering the different mechanism of self-stress formation, a new type of structure was proposed for expansive grouted clamp, which is used for underwater repair on steel tubular. Since the structure is changed totally, the corresponding design method should be modified. This paper summarizes a design method of the new type of expansive stressed grouted clamp and sorts out a set of practical design procedure for the new structure. The core principles of the design method are based on the checks on slip capacity, member crushing and structural strength, associated with the experiment data and previous design experience as reference. An example of such clamp design for repairing a horizontal brace of a jacket platform is also introduced to describe how this method works.

Abstract: As wind-induced damage always occurs at the roof of storey factory, the roof pressure of storey factory under different wind directions was analyzed based on the Realizable k-ε turbulence model. Hexahedral element based numerical modeling was chosen, and the pressure-linked equations were solved with fast-convergence SIMPLEC algorithm. The results showed the wind pressure at the leading edge from the windward side is far greater than other regions of the roof, indicating this area should be the main issue in wind-resistant design.

Abstract: Floor loads of the large-bay floor can cause larger bending moment at the floor edges. So the shear-wall need to bear greater out-plane bending moment and this problem can not be ignored. multi-ribbed slab structure is a new wall. The paper Calculated out-plane bending-stiffness of multi-ribbed slab by using the equivalent-stiffness method. The results show that: the equivalent stiffness method is simple and ribbs should not be too large, width-height ratio control between 1 and 3, wall length is about 5.4m.

Abstract: This paper studied 30 cold-formed steel columns with three different sections and eleven different eccentricities under eccentric compression loading by nonlinear finite element analysis using program ANSYS. Effects of the above parameters on ultimate load-carrying capacity, buckling modes, the distribution of stress and strain, and deflection behavior of channels with complex edge stiffeners under eccentric compression loading were investigated. The result shows that influence of the effective centroid offset on carrying capacity under eccentric compression loading can not be ignored. The maximum of ultimate load-carrying capacity appeared when effective eccentricity was 0mm, and decreased with the increase of the value of effective eccentricity. Sections influence on load-carrying capacity under negative eccentric compression loading. Web stiffening can improve load-carrying capacity which the eccentricity near the web side. Sections influence on buckling modes. web stiffening can effectively avoid local buckling.

Abstract: This paper mainly focuses on the affect factors of ductility of reinforced concrete pier with the high-strength longitudinal reinforcement and stirrups. By finite element software ANSYS, changed the amount of longitudinal reinforcement and high-strength stirrups in the piers, the ductility performance of concrete piers was studied. The results show that under certain conditions, the ductility coefficient of concrete piers with high-strength reinforcement can increase with the amount of stirrups. In addition, high-strength longitudinal reinforcement can improve the ductility performance of the concrete piers, but it should be controlled in a reasonable range. If there are too much high-strength longitudinal reinforcement in the concrete piers, the ductility performance will be lower, and structural seismic performance will also be affected.

Abstract: Anchors group system, whose spacing and edge distance could not meet the requirements of the code, were tested. Based on the test, the finite element models involving geometric and materials nonlinearity were presented. The finite element analysis (FEA) were proved to be reasonable by comparing the results of FEA to the results of test. Anchors systems of spacing and edge distance from 2d to 9d,under tension load were simulated. It turned out that, the maximum bearing capacity of anchors group system was achieved when the spacing and edge distance were 8d, which was 40% bigger than the one of 5d. The minimum bearing capacity of anchors system was obtained when the spacing and edge distance were 3d, for the destroyed areas of concrete of adjacent anchors overlaped. Anchors group system of spacing and edge distance smaller than 5d still could be used through reducing the ultimate bearing capacity by a factor γ_sc. The formula ofγ_sc was obtained through numerical analysis method.

Abstract: Traditional design of structural members is considered less collision effects, so it may be possible to cause damage due to impact loads. In view of this, impact-resistant performance of the concrete wall with different protective layers was analyzed. In the process of the numerical simulation, the observed walls with three different measures including the unprotected, the rigid protective and the flexible protective one were considered separately. Protective effects of the different measures were compared and analyzed by observing the stress, the strain, the velocity and acceleration of the target wall. Numerical results show that the flexible protective system works better. The flexible protective layer of the wall may have a significant impact on the protective effect such as suppression of the peak impact response.

Abstract: The problem of loss of prestress and compensation of prestress of Fish-Bellied Beam Support exist in foundation pit construction but seldom be considered in design. Finite Element Analysis on an existed foundation pit engineering of prestressed Fish-Bellied Beam Support by using finite element software ABAQUS. Discussed the influence on lateral deformation of foundation pit caused by loss of prestress and compensation of prestress.The results show that the influence on lateral deformation of foundation pit caused by loss of prestress and compensation of prestress is remarkable, and existing a critical loss percentage, lateral deformation of foundation pit will be well controlled by adjusting compensation of prestress in terms of considering the critical loss percentage.

Abstract: This paper presents the results of static tests of round timber bolted joints with inserted steel plates. All round timber joints static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. At first, timber specimens were tested without reinforcement. Based on these results, mechanical reinforcement methods were proposed: using modified washers and boost with screws. These samples were also tested. Rate of improvement in tensile strength was established for used reinforcement method.

Abstract: Aim of this article is in presentation of results of dynamic tests of round timber bolted connections with slotted in steel plates. Multicyclic dynamic (fatigue) tests in tension were made with round timber joints on pulsator INSTRON in laboratory of ITAM CAS Prague. Results of laboratory tests have been statistically evaluated and completed with graphical records of deformation response to loading.