Applied Mechanics and Materials Vols. 166-169

Abstract: Movements of pulse shape and the high energy applied in short duration by the near fault earthquake, causes brittle fracture in rigid connections that during the Northridge 1994 and Kobe 1995 earthquakes was frequently seen. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “TSW semi-rigid” connections under the near fault earthquakes with nonlinear time history analysis by perform 3D software.

Abstract: Based on China building seismic code (GB5011-2010), an overview about base-isolated designing method is presented in this paper. The composition of base-isolated structure, design process, design content, application in practical engineering are involved .The purpose of this paper is to make structural engineers have an overall understand about base-isolated structure design, and promote the further application of this kind of structure in China.

Abstract: In this paper , the lead-rubber bearings and viscous dampers are proposed to be used as the seismicity mitigation and energy dissipation devices at the connections between the deck and pylons of single tower cable-stayed bridge. The bilinear model and Maxwell damper model are also used to respectively simulate the hysteretic behavior of the bearings and dampers. Finally, the effects of the seismicity mitigation and energy dissipation of the bearings and dampers are investigated through the nonlinear seismicity analysis method of the structure. The results show that the lead-rubber bearings as the bearings and dampers connect ion of the single tower cable-stayed is an effective method to reduce seismic forces.

Abstract: The probability density evolution method (PDEM) for random earthquake response analysis of non-linear structure is constructed by incorporating orthogonal expansion method for earthquake ground motion into the PDEM. In this method, seismic acceleration process is represented as a linear combination of deterministic functions that are modulated by 10 uncorrelated random variables. The stochastic seismic response analysis and reliability evaluation of nonlinear structures under earthquake excitations will be successfully carried out if the above methods can be combined together. In order to validate the proposed method, the author takes a nonlinear frame structure subjected to ground motion as an example to illustrate it.

Abstract: A two-dimensional finite element model for soil-subway station- high rise building was created based on the representative soft soil site along the Nanjing subway to study the nonlinear dynamic interaction among three parts. The influence of two-layer and three-stride island-type subway station was explored on the seismic response of nearby high rise building. The results showed that the natural frequency of high rise building was reduced apparently because of the existence of soft soil. The displacement angle between the layers of high rise buildings and right swing relative horizontal displacement amplitude between top and bottom was increased when the subway station was located at the left of the high rise building. In the same time, the shear force of the beam end and the moment amplitude on the middle span of the first and second floor of high rise building, the shear force of the column end on the fist layer, the shear and moment amplitude of the middle column end and right side column end on underground layer were all increased, and the increase proportion is even up to 30% on certain areas, which could weaken the seismic performance of high rise building.

Abstract: The advances in seismic research of long-distance transportation pipes in recent years which includes four major aspects such as the harm of earthquake to long-distance transportation pipes, the seismic research methods of long-distance transportation pipes, seismic analysis and measures of long-distance transportation pipes were introduced, and the coming research directions were also pointed out in this paper.

Abstract: In general, the higher story of the building, the stronger effects on humans and objects. In this paper, seismic response analysis for two buildings is carried out. The time histories of displacement, velocity, acceleration and acceleration response spectrum of each floor are obtained. By analyzing these results, the phenomenon of "the higher story of the building, the stronger effects on humans and objects" is demonstrated. And reasons of this phenomenon are preliminary analyzed.

Abstract: Seismic excitation of linearly elastic structures is dealt with in the paper. It is well known that dynamical structural response is very sensitive to random fluctuations of the excitation; the consequence is that the identification of the forcing function on the basis of a few global parameters does not allow to predict exhaustively stresses in seismically excited structures. In the paper, a convex model is established to treat uncertainty associated with the details of the excitation. In order to set bounds on the response parameters of a SDOF system, assuming that only rough information is available for expected earthquakes at a given site. In particular, we assume that the maximum expected energy of the acclerogram, and the maximum distance of its power spectrum from the target spectrum, typical for the site under construction, are specified.

Abstract: The finite element analysis method was used to analyze the seismic response of two oil pipelines, which have corrosion defects and no defects correspondingly. The velocity, displacement and acceleration time history of the two pipelines and the contrastive analysis of the maximum stress of two pipelines were obtained. The results show that the displacement, velocity and acceleration of the pipeline with corrosion defects are larger than those of the pipeline without corrosion defects, the corrosion has great influence on the bottom of the pipeline, and the influence also has certain wide, the farther away from the corrosion, the smaller the influence is.

Abstract: The serious soil liquefaction phenomenon in Bachu-Jiashi earthquake on 24th February, 2003, which is the most prominent phenomena of sand liquefaction since the Tangshan Great Earthquake in 1976. Based on the earthquake liquefied investigation, inspect SPT and CPT applicability in situ tests. The results show that our country SPT specification and CPT specification of non-liquefied sites evaluation rate is higher than liquefied sites evaluation success rate, the liquefied sites evaluation rate are 88% and 88% respectively, but for liquefied sites evaluation rate are 38% and 55%. The result is tends to danger and the reason need further investigation, so establish a suitable liquefied prediction method should be to the future work in the local area.