Shiyun Xiao

Lessons Learnt from Building Damages in the Wenchuan Earthquake

The earthquake Ms=8.0 at Wenchuan county of Sichuan Province in China happened on May 12, 2008. In the strong seismic area, engineering structures were badly damaged in various grades or collapsed. This paper focuses on the description and analysis of the damage phenomena of engineering geology, buildings and lifeline engineering structures based on the on-site investigation of the earthquake damage. Finally, some valuable lessons learned from this big earthquake are presented including the suitable building structures should be chosen for important buildings to resist the seismic action in the strong earthquake area when the building is designed; the concept design and applications of energy-absorbed and vibration-reduced techniques should be paid attention; the comprehensive safe evaluations for the existing buildings should be done in the strong seismic active area; the seismic designs and researches on bridges and pavement should be emphasized, and the seismic design and research on facilities of communication, and power and water supplies should be regarded as key issues to make the facilities expedite for disaster rescue after earthquake. The content in this paper may be as a reference to seismic design of buildings, reconstruction of disaster area and revision of corresponding codes and regulations.

Impact of Flood on a Simple Masonry Building

AbstractIn this paper, the impact action of a flood on rural mountain buildings is systematically studied. First, based on the one-dimensional Saint-Venant water equation explicit-difference scheme, a new explicit-difference scheme is deduced to establish the evolutionary routing model of a flood. A computational formula about the impact loading of the flood model is deduced. Secondly, an impact experiment of a flood on buildings is carried out in a large wave-current tank. The heights of the water are 0.6, 0.9, and 1.2 m, and the distances between the building and floodgate are 3, 6, and 9 m, respectively. The model scale of the buildings is 1:6, and three buildings with different ratios of holes are designed to simulate the buildings in countries and villages. Based on the experimental results, the effects of the heights of the water, the distances between buildings and floodgates, and the ratios of holes on the impacting pressure are investigated. The numerical results are compared with the experimenta...

Rate dependent plastic–damage constitutive model of concrete

Abstract Generally, on the plastic and damage constitutive model, the plasticity consistency condition of the yield function and the damage consistency condition of the damage evolution could not be satisfied when the effect of strain rates was taken into account. The viscoplastic strain was determined by the viscoplastic flow theorem. In this paper, the rate dependent consistency plastic–damage model of concrete is proposed by imposing the consistency condition for the yield function and the damage evolution criterion. The Drucker–Prager yield function and the damage evolution criterion proposed by the authors, taken into account the effect of strain rates on dynamic behaviours of concrete, are adopted. Based on these assumptions, the dynamic damage evolution equation and the constitutive model of concrete are deduced. Then, a numerical algorithm similar to Euler backward mapping schemes for rate independent plasticity is proposed by the authors to calculate the rate dependent plastic–damage model of concrete. Finally, the model is compared with the uniaxial tensile and compressive damage experimental results.

Numerical Analysis of the Rural Building due to Flood Impact

The impacting action of flood destroyed dramatically the rural buildings. In this paper, the rural building was analyzed numerically to investigate the destruction of rural building due to the flood impact. The rural building was discretized into 7950 8-node block elements and 4098 Goodman elements to simulate the brick and mortar respectively. The rule impact loading of flood on rural building was calculated using the criterion of gravity similarity according to test results. Finally, the stress, the displacement and the failure process of the rural building are studied. Firstly, the mortar element locates on the wall between the door and the window failure and more and more mortar and brick elements failure with the increasing loading. Finally, the right wall was damaged because the door and the right window decreased its stiffness. Because the failure mortar and brick elements decrease the stiffness of the structure, the displacements of the rural building increased nonlinearly with the increasing loading.

Three-dimentional visual design of rural buildings based on OpenGL

The impacting action of flood destroyed dramatically the buildings, which caused the vast people and economic losses. It is important to analyze and design the rural buildings to resist the flood. In this paper, considering basic characteristics of rural building structures, the three dimensional models of rural building were built, with the help of windows operating system, MFC framework of VC++ and OpenGL graphics technology, during this process the parameters were input by parameter dialog box. And then the three dimensional model under flood impacting was displayed to show the physical variables of rural housing construction. The drawing of the model on the screen can be scaled, so a friendly Man-computer interactive interface can come true with changing the interactive observation position in 3D space. It is proper to analyze directly and generate the simulation model of rural buildings, and convenient for analyzing and designing software of flood acting on rural buildings.

Model of Transmission Tower-Pile-Soil Dynamic Interaction Under Earthquake: In-Plane

In this paper, the mechanical model of Soil-Pile-Structure interaction of transmission tower-cable system in in-plane is presented and the corresponding equations of motion are derived, in which the nonlinear characteristics of soil is included in the dynamic time history analysis. The computer program for the system is complied and used to calculate the earthquake response of an actual transmission tower. The results of numerical calculation are compared with and without considering soil-pile-structure interactions, which show that the dynamic interaction should be taken into account in the soft foundation.© 2002 ASME

Effects of Water Height and Floodgate Distance on Flow Pressure of Flood

Rural building models were tested to research the action of flood on buildings, three different water heights with 0.6, 0.9 and 1.2 meters were applied to this experiment to simulate small-scale, medium-scale and large-scale flood respectively. The model was placed at 3, 6 and 9 meters far from the floodgate. In this paper, the effect of the water height and the distance between model and floodgate on the values and distributions of the flow pressure are studied. Some conclusions can be drawn: the flow pressures, force and bending moments of the flow surface increase with the increasing water height and the relationship are approximately linear; the values and distributions of the flow pressure are independent of the floodgate distance and the force and bending moment of the flow surface increase with the distance from 3 meter to 6 meter but decrease with the distance from 6 meter to 9 meter.

Experimental Study on Flow Pressure Distribution of Flood on Rural Buildings

Recently, frequent torrential floods cause tremendous casualties and economic losses to the national people in China. In this paper, six 1:6 scale rural building models made of PMMA are tested to research the flow pressure of flood, which will provide the basic data for the flood-resistant design of rural buildings. The experiment of flood on buildings is carried on the large wave-current tank. The height of water is 0.6, 0.9 and 1.2 meters and the distances between the building and floodgate are 3, 6 and 9 meters respectively. The flow pressure is obtained by the sensor transducer. Based on the experimental results, the distribution of the flow pressure and some effect factors are investigated. Results show that the variation of flow pressure distributions decreases gradually with the vertical distance from bottom to top in the vertical direction. The flow pressure in the horizontal direction is different because of the boundary and holes effect.

Seismic Damage Characteristics of RC Shear Wall with Diagonal Profile Steel Braces by Experiment

This paper focuses on an experimental investigation and theoretical analysis of different types of RC shear wall with the profile steel braces in two side columns and diagonal profile steel braces of walls subjected to applied repeated cyclic loads. Fifteen RC shear walls with different shear span ratio are tested and their aseismic charactertics are studied. The effect of profile steel bracings on failure property, bearing capacity, ductility and hysteretical characteristic of shear wall is investigated based on experimental results. It is shown that adding the profile steel braces on the boundary column and inner of walls can obviously enhance the ultimate strength of specimens and improve their aseismic characteristics. Finally, the mechanical model of the shear wall is presented and the formulae for calculating the load-carrying capacity are developed. Numerical analyses indicate that the theoretical results agree well with those from experiments.

Experimental Study on Aseismic Characteristics of RC Shear Walls with Diagonal Profile-Steel Bracings

This paper focuses on an experimental investigation and theoretical analysis of different types of RC shear wall the profile steel strengths in two side columns and diagonal profile steel braces of walls subjected to applied repeated cyclic loads. Fifteen RC shear walls with different shear span ratio are tested and their aseismic charactertics are studied. The effect of profile steel bracings on failure property, bearing capacity, ductility and hysteretical characteristic of shear wall is investigated based on experimental results. It is shown that adding the profile steel braces on the boundary column and inner of walls can obviously enhance the ultimate strength of specimens and improve their aseismic characteristics.