Advanced Materials Research Vols. 243-249

Abstract: Experimental research was conducted on the transverse stress of 32m post-tensioned precast simply supported concrete box girder with ballastless track. Vibrating wire strain gauges were embedded in the key sections to monitor the concrete transverse strain. The concrete strain development law was analyzed. The monitored results showed that there were low transverse tensile stresses and the cracking resistance of the girder was enough during pre-tensioning stage. The research findings provided effective experimental data for design and construction quality control.

Abstract: This paper is a case study of Wu’s house, which is located at the Majiamiao hutong, only several blocks away from the imperial palace—the Forbidden City in Beijing. It is a typical quadrangle called Siheyuan, or "four-side enclosed courtyard". Historians declared that, judging by the architectural style and interior decoration, the house might have been constructed in the late Ming dynasty [1], which means the history of the house could go back for more than 400 years. The complete story of the house and its owners can be divided into three parts: first, a house for a large feudal family before 1949; secondly, a house for a famous dramatist until 1966; and finally, a house for the city poor from the Great Cultural Revolution on. During 400 years of social evolution and revolution, especially in the past 50 years, the house and the families who lived in it underwent great changes. The precise homology and strict hierarchy in Siheyuan, implied by the order of orientation and scale of the buildings within the house, was weakened gradually by the “revolutionists” who tried to establish an absolute equality among the people in every detail of their lives, including their house. However, never will a house like Siheyuan be equal to every member in it because it was born of politics.

Abstract: The field transfer matrixs and the point transfer matrixs can be established by the transfer matrix method, which can solve the internal forces and deformations problems of each cross-section, based on the solutions of deflection differential equation of the curved bridge. The bending-torsional coupling, horizontal bending and axial deformations should be considered into the structural analysis of the curved bridge, under the influence of curvature. To establish the general transfer equation requires the field transfer matrixs and the point transfer matrixs of the curved bridge in horizontal and vertical directions. The state vectors of each cross-section can be obtained depending on the general transfer equation.

Abstract: For the arrangement of suspender and arch rib in the combination of beam and arch bridge, the finite element model is established according to the background of practical engineering. The influence of the variations of structure design parameters on structure characteristics of the static and dynamic is analyzed. The calculation results show that the different layout of suspender has small effect on the axial force variations of tie beam and arch rib, but has bigger influence on the bending moment of partial section. The structural transverse basic frequency augments with increase of arch rib leaning-angle, the vertical and twisting basic frequency is larger when the leaning suspender and netted suspender are used. The arrangement of suspender and arch rib should be optimized in the design of similar bridge.

Abstract: In order to overcome the disadvantages of traditional binding mortar with its workability is poor, bond strength is low, and the bond effects far from satisfactory. In this paper,binding mortar, has been developed by adding polymer into mortar to improving the binding strength and workability. The effects of the polymer type and content on strength of mortar has been studied,The results show that polymer-modified bonding mortar worked better than the traditional mortar: the workability was improved, bonding strength was enhanced.

Abstract: Through dynamic performance test on prestressed concrete simply supported beam of Xiaotang-river Bridge on the Suhuang railway under different speed and different train formation, the dynamic characteristics of the bridge and its response under speed-increase trains are studied. Results indicate that the lateral forcing vibration frequency of train is close to the lateral natural vibration characteristics of the bridge when trains running at 70 and 75 km·h^-1, and the resonance occurs. Consequently, vibration restraining measure for PCT beam should give priority to increasing the lateral rigidity of beam. When train speed exceeds 60 km·h^-1, the maximum lateral amplitude of PCT beam exceeds the safety 1imit with no exception. The values of the lateral and vertical vibration acceleration of PCT beam are under the safety limits regulated by Code for Rating Existing Railway Bridges. The lateral vibration frequency of PCT beam in mid-span is obviously on the low level and is only 40-50 percentage of the reference value. The vertical natural vibration frequency of bridge in mid-span is enough and the ratio of vertical deflection and span is lower than the ordinary value stipulated in Code for Rating Existing Railway Bridges. It shows that the vertical rigidity of the beam is enough. Different formations of passing trains have a great influence on the 1ateral amplitude. When train formation is C₆₄, the lateral amplitude is the maximum. while train formation is C_64K, the lateral amplitude of the beam is smaller.

Abstract: Combining the scientific research project- the study on cable-stayed suspension bridges, with the engineering background of Dalian Gulf Bridge to be built, this paper focuses on the seismic effect of non-linear viscous dampers on Self-anchored Cable-stayed Suspension Bridge. Based on the non-linear dynamic time-history analysis, the parameter sensitivity of damping coefficient and velocity exponent is analyzed. Through the analysis results, the proper dampers are decided. The seismic response result of before setting dampers is compared with that of after setting dampers. The results show that viscous dampers not only can greatly reduce the relative displacement and inner force under seismic effect of key positions of Self-anchored Cable-stayed Suspension Bridge, but can efficiently minimize the damage caused by earthquakes on bridge structure without changing static force behavior, which can provide evidence of seismic design for similar bridges.

Abstract: The problem and relevance research of tension test technology of cable and suspender was introduced from the influence of environmental factors, cable stiffness identification, equivalent length, sag, slope, testing techniques improvement, numerical analysis with curve fitting, and boundary conditions of elastic support. And according to the actual needs of tension measurement in engineering the researches on cable tension measurement maybe highlight were prospected.

Abstract: Under the great background of economic globalization, high-speed development of airplane and automobile industry as well as Harbin Aviation and Automobile Industry City as one of national aviation industry bases, this paper conducts a systemic study on Harbin Aviation and Automobile Industry City. Upon the basis of study on the development background as well as current situation of the industry city, regional overall planning, land utilization, urban function, ecological landscape and culture as well as other planning and development strategies of the industry are mainly discussed in this paper, and, hereby planning prospects are put forward so as to provide certain reference for the planning and construction of industry cities.

Abstract: The externally prestressed bridge finite element analysis module redeveloped based on ANSYS software is introduced，realizing finite element analysis method for externally prestressed concrete bridge. It is able to build the externally prestressed bridge finite element model, combined with Solid65 and Solid45 simulated concrete, and Link8 or Link10 simulated prestressed tendon. It is also able to bring material and geometric nonlinear effects into the analysis, for analyzing ultimate bearing capacity and local stress characterization of the externally prestressed structure. A bridge model is generated as an example for verifying the application of the module. Based on it, the model then is equipped with different allocation arrangements of internal and external tendons to analyze the mechanical characteristics of externally prestressed concrete bridge. Research is conducted for the effect on ultimate bearing capacity by allocation arrangement of tendons, and providing design suggestion and theoretic basis.