摘要: This paper addresses the stability behaviour in-plane and the critical load of the double-hinged circular steel arch when subjected to elevated temperature caused by fire, the study is restricted to the thermoelastic structural response of the steel material and therefore the high-temperature effects of yielding are not considered. In order to model structural response of the steel arch under thermal loading, some significant factors such as the degradation of the stiffness of the steel arch prior to yielding at elevated temperatures is taken into account, the formulation of critical load is proposed and their variation trends with temperatures is analysed. The proposed method has significant potential for use in the analysis of steel arches subjected to uniformly distributed load at elevated temperature and can provide a foundation for codified procedures in design.
摘要: In order to optimize the design of foundation pit support in specific areas of soil conditions, the equivalent angle of internal friction was put forward to instead of internal friction and internal cohesion based on the theory and practical engineering experience. Then the optimization design of calculating parameter for soil pressure was realized. At the same time, the optimization of protecting piles design become reality that based on the circular section piles convert to the rectangular section piles through equal stiffness according to its characteristics. Through the application of the optimal design method in a practical engineering, the result proved that the method improves the anti-overturning ability of the soil and saves the engineering cost of the piles.
摘要: Compared with reinforced concrete shaped columns, bearing capacity and ductility of steel reinforced concrete shaped columns are significantly improved, so it is with theoretical significance and practical application of value to research. Based on the plain cross section presume, with material cross-section boundary calculation unit, 15 steel reinforced concrete cross-shaped columns(SRCCSC) have made nonlinear full-rang numerical analysis. It demonstrates that the most adverse curvature ductility load angle of SRCCRSC is 45°.Loading angle (), axial compression ratio (n), and the ratio of spacing and diameter of longitudinal reinforcements (s/d) are the principal factors in curvature ductility of SRCCSC subjected to biaxial eccentric compression. Under the most unfavorable loading angle, through a regression analysis of curvature ductility computer data of 150 cross-shaped columns with 8mm stirrups diameter and 150 columns with 10mm stirrups diameter, it can be obtained with the relationship betweenand axial compression ratio n,s/d, of SRCCSC subjected to biaxial eccentric compression.
摘要: The primary goal of failure modes-based optimization design which is to study the performance of structure without shocking absorption device is to transform the non-ideal failure modes of structure into the ideal failure modes, and then a small probability of the structure damage can be obtained. Although the study of this field is significant, no paper has so far attempted to study. Taking the cost of the structure into consideration, this paper aims at the failure modes-based optimization design. Therefore, an optimal approach based on failure modes with the ability to limit the cost is proposed. The procedure to obtain the failure modes-based optimization includes two phases, the concrete optimization and the shaped steel optimization. At last a reinforced concrete frame-shear wall structure is cited to verify the method developed. It is concluded that the method can supply an effective way to reduce both the damage and the cost of steel reinforced concrete framework-core tube structure.
摘要: Southern surveying and mapping instruments company CASS terrain, cadastral mapping software is based on AutoCAD platform technology of digital mapping data acquisition system. Widely used to terrain mapping, cadastral mapping, engineering survey three major areas of application, by using terrain mapping, cadastral mapping software of CASS7.0,the author explored a method about using terrain mapping, cadastral mapping software of CASS7.0 to drawing profile map, through the application for line project theoretical and practical research to achieve the desired effect, solved the problem by using terrain mapping, cadastral mapping software of CASS7.0.
摘要: The full replacement of plain concrete with ultra-high toughness cementitious composite (UHTCC) in structural members can obtain the enhanced structural performance over traditional concrete structures because of its prominent advantages such as the markedly ductile deformation capacity after post-cracking and excellent damage tolerance ability. In the current article, aimed at setting up the theoretical formula for the practical use in the bending design of reinforced beam made of UHTCC, the equivalent parameters introduced in rectangular stress block approach are analytically determined. Two existing models in compression for UHTCC, i.e., bilinear model and parabolic line then horizontal line (nonlinear model) are adopted in the derivation of the equivalent parameters. By comparing moment-curvature curve obtained from the experiment with the calculated one, the nonlinear model is verified to be rational and could predict bending capacity with sufficient accuracy. Further comparison between moment-curvature curves calculated according to two compression models shows that the nonlinear model can give a bending response prediction with almost the same accuracy as the bilinear model. Finally, it is suggested that, in the case that nonlinear compression model is adopted for the compressive behavior in UHTCC, the equivalent parameters α=0.8 and β=1.0 could be used to estimate ultimate load bearing capacity of reinforced UHTCC beam.
摘要: Wall slip of sweage sludge and affect slip possible factors were studied experimentally by using a rotational rheometer with parallel plate fixtures and by means high speed camera. In the steady shearing flow, the technique involves placing a straight line marker monitoring of wall slip,checking the gap dependence of the stress/ strain data. For sweage sludge of water content 80%, in the shearing flow it was found that, as the strain amplitude increasing, the stress data obtained at different gaps, then, at the certain strain amplitude, started to diverge, indicating that wall slip occurred. But for sweage sludge of water content 90%, these curves are superimpose, indicating no slip occurred. In the dynamic oscillatory shear flow, we analyze the total wave. While strain, stress amplitude decreases with the time, while strain, the stress amplitude remains constant.
摘要: Concrete casting effect and the hooping effect of concrete filled tubular members is considered in the study of this paper. Firstly, standard stress-strain relationship of concrete and steel is chosen to simulate others’ test, and meanwhile the calculation results by nonlinear finite element analysis are compared with the results of the test. Then the bearing capacity of horizontally casted concrete filled steel tubular members under axial compression is contrasted among different construction processes. Finally, the effect of slenderness ratio of concrete filled tubular members is studied so as to reveal the relationship between the bearing capacity and slenderness ratio.
摘要: According to the existed theory foundation, the authors made a simulated analysis on mechanical properties of a connection between steel reinforced concrete filled with steel tube column and steel beam, using ABAQUS, which is a finite element software. The authors established element model reasonably, and got load- displacement curve in different axial compression ratios. According to the result, with the increasing of axial compression ratio, the elements' limit bearing capacity reduces significantly.