Advanced Materials Research Vols. 368-373

Abstract: To study the fire performance of the profiled sheet-light aggregate concrete composite floor subjected to fire load, study of fire response and post-fire bearing capacity of a profiled sheet-lightweight aggregate concrete composite floor subjected to dead load is carried out. Based on the experimental results, the fire performance and post-fire bearing capacity of the floor after exposure to fire are analyzed. It is shown that the failure form of the profiled sheet-ceramsite concrete composite floor after exposure to fire still exhibits higher bending capacity, and the ultimate value of the equivalent distributed load is up to 30.69kN/m², which may be used as basis of strengthening and repairing of the profiled sheet-ceramsite concrete composite floor after exposure to fire.

Abstract: To study dynamic response law when the isolated structure eccentric, random vibration of eccentric isolation structure is analyzed by generalized frequency response function in different structural parameter and site conditions, soil conditions, and isolation layer use the equivalent linear model, the structure level-torsion coupled vibration characteristics are considered. By calculation, statistical law of structure random dynamic response of eccentric isolation structure under seismic waves is given.

Abstract: In this article,by incorporating equivalent linearization method and the orthogonal expansion method into the wave finite element analysis of scattering problem, an analytical methodology for the evaluation of seismic response of nonlinear soil site with uncertain properties is proposed . Example is given to show the applicability of the methodology. The results show that the randomness of the site media has important effect on seismic site response , the randomness has greater influence on the variation of accelerations than on displacements. The coupling of the nonlinearity and the randomness of soil enhances the effect of randomness on the soil site.

Abstract: The vibration of buried pipeline is influenced by inner fluid and outer constrained soil. Euler-Bernoulli beam is analyzed in the vibration model of buried pipeline, using the Hamilton principle. In addition, the differential equations of transverse vibration of buried pipeline deduced by the mechanical model are transformed into basic form of dynamics equations, considering earthquake excitation as random wave. Using the method of the elasticity time-travel analysis to programming, the pipe element, the soil parameter and the earthquake dynamic parameter are analyzed in the Matlab software. With soil from soft to hard, the response of piping displacement becomes smaller and smaller. In the same soil, the earthquake damage rate of the piping becomes increaser and increaser with earthquake intensity increasing.

Abstract: Being aimed to deformation problem of pre-stressed concrete thin-walled multi-room box girders exposed to co-action of fire and load, on the basis of enthalpy conduction model and thermo-mechanics parameters, the finite element procedure was applied to analyze the deformation of three spans pre-stressed concrete thin-walled multi-room box girders exposed to co-action of fire and load. In conclusion, the deflection is obvious under action of the variation width and fire load model.

Abstract: In the recent years, the wind energy building is rapidly developed world wide as a new kind of building style, for its low price and it’s friendly to environment. The wind energy building a combination of wind power and buildings, it could turn wind power into electric energy, which also could relieve the energy scarcity problem to some extent. The wind driven generator and high-rise building structure were integrated, and ANSYS was used to complete the analysis of the behaviors of structures with and without wind generator, under EI-Centro earthquake wave and Taft earthquake wave. By comparing the results of those two models, the feasibility of the wind energy and building integration was verified.

Abstract: This article summarizes the work regarding the complex and viscous damping models of SDOF system. Through calculating dynamic equations based on harmonic excitation, the result is that: when the excitation's period is less than the structure natural period, the displacement, velocity, acceleration responses of the complex damping system are stronger than the latter. Further, the displacement and the velocity spectra of some representative earthquake records are provided of two models, which show the similar trend as harmonic excitation. But the absolute acceleration spectra values of the complex damping model are higher than the other one at most time. And generally with the growing damping ratio and structure natural period, the difference is more significant. Under certain earthquake records, the structure displacement spectra values may differ by 17%, the velocity values differ by 20%, the acceleration values differ by 15%.

Abstract: Six specimens of abnormal interior joints were tested under reversed cyclic loading. Experimental studies were carried out to investigate the influence of joint core dimensions and axial compression ratio on crack resistance of abnormal joints. The results showed that the crack resistance capacity was mainly provided by the minor core concrete (determined by the top column and the small beam) , and the minor core concrete was in elastic stage before cracks appeared. Furthermore, axial compression ratio was a significant parameter to increase the crack resistance capacity. Based on the test results, a theoretical formula of crack resistance capacity was proposed. The calculated crack resistance capacities of 11 abnormal interior joints were compared with the experimental results, and a good agreement was obtained.

Abstract: According to earthquake hazard, normal frame structures could hardly avoid failure of ‘Strong Beam and Weak Column’, weak layer and even progressive storey collapse under strong earthquakes, a main reason is the lack of second seismic fortification line in frame structure. Based on the design thought of multiple seismic fortification lines, reinforced concrete twin-frame structure is initiated in this paper. Major feature is increases of redundant constraints and load paths due to added outer limb-columns could take effect as the second seismic fortification line. Twin-frame structure could not only fulfill the demand of ‘three levels, two stages’ in seismic code, but also have been designed through the third stage of ‘resist progressive collapse’, using key member method to promote safety storage and deformability of outer limb-columns, using removal key member method to verify vertical ultimate load of frame beams in weak layer. Though twin-frame structure could not completely avoid plastic hinges in column ends, progressive storey collapse will not appear in this kind of structure. Twin-frame structure is a new structure system which could be applied in constituting new projects as well as strengthening and rebuilding existing projects, further research can be done on this structure system.

Abstract: Correctly analyze the formation mechanism and failure mode of the landslide and reasonably evaluate the stability of landslide, can provide scientific basis for landslide controlling. Employed the field investigation, field monitoring, indoor experiment and numerical simulation methods to carry a systematic study on the stability condition and formation mechanism of the Bei-Hei expressway expansion project K178 landslide, the results show that: the silty clay which is loose when dried, and is soft plastic when saturated glides along the surface of bedrock; the safety factor during surveying is 1.21, the landslide is temporarily in a steady state, when the water content of rupture surface soil is increased to 30.5% , the safety factor will reduce to below 1.0, the landslide will be instability; atmospheric precipitation, snowmelt water and seasonally frozen soil thawing water provide water for landslide, cracks and high permeability of main body soil provide passage for water infiltration, mudstone and sandstone with low permeability form aquifuge, silty clay above the aquifuge which is influenced by infiltration water to reach saturation forms rupture surface.