Key Laboratory of Civil Engineering Safety and Durability

Beijing, China

Key Laboratory of Civil Engineering Safety and Durability

Beijing, China
SEARCH FILTERS
Time filter
Source Type

Kang Y.,Tsinghua University | Kang Y.,Southwest Research Institute | Yang J.,Key Laboratory of Civil Engineering Safety and Durability
2011 International Conference on Electric Technology and Civil Engineering, ICETCE 2011 - Proceedings | Year: 2011

A building was designedly blasted to partly ruined one to model a seismic damaged structure in the earthquake ruins training field of the National Training Base of Emergency Seismic Rescue. The structure design method of this case is discussed here, including the earthquake load design level, two separate models in PKPM, and the intended weak section design for the blasting to control the ruin shape. A numerical simulation is carried out by using ANSYS/LS-DYNA, modeling the whole procedure of the blasting and the collapse of the building. The results showed that this simulation is quite successful and the final shape of the ruin is exactly the wanted one and proved by the real blasting. Several key issues in the simulation are discussed also, such as the connection technique of slab, beams and columns in the FEM mesh and the right choice of the material properties. © 2011 IEEE.


Han L.-H.,Tsinghua University | Han L.-H.,Key Laboratory of Civil Engineering Safety and Durability | Wang W.-D.,Tsinghua University | Wang W.-D.,Key Laboratory of Civil Engineering Safety and Durability | Tao Z.,University of Western Sydney
Journal of Constructional Steel Research | Year: 2011

This paper presents the study on the behavior of composite frames with circular concrete filled steel tubular (CFST) columns to steel beam. Six composite frames were tested under a constant axial load on the CFST columns and a lateral cyclic load on the frame. Each frame specimen consisted of two CFST columns and a steel beam to represent an interior frame in a building. A finite element analysis (FEA) model was developed to investigate the behavior of the composite frame. The results obtained from the FEA model were verified against those experimental results. Detailed analysis was carried out on longitudinal stress in steel beams, axial stress distribution in concrete, concrete stress along the column height and at the connection panel. Parametric studies were conducted to investigate the influence of axial load level, beam to column linear stiffness ratio on the structural behavior of composite frames. A simplified hysteretic lateral load (P) versus lateral displacement (Δ) model was proposed for such composite frames. © 2011 Elsevier Ltd. All rights reserved.


Han L.-H.,Tsinghua University | Han L.-H.,Key Laboratory of Civil Engineering Safety and Durability | He S.-H.,Tsinghua University | He S.-H.,Key Laboratory of Civil Engineering Safety and Durability | And 2 more authors.
Journal of Constructional Steel Research | Year: 2011

This paper reports the behavior of concrete filled steel tubes (CFST) under axial tension. A total of 18 specimens were tested. The main parameters were steel ratio, concrete type and bond or unbonded between the steel tube and its core concrete. A finite element model (FEM) was developed to perform mechanism analysis and parametric studies for CFST under axial tension. It was found that the tensile strength of steel tube can be increased due to the existence of the core concrete in CFST. Finally, a simplified formula that can predict the tensile strength was proposed. © 2011 Elsevier Ltd. All rights reserved.


Ye L.,Tsinghua University | Ye L.,Key Laboratory of Civil Engineering Safety and Durability | Lu X.,Tsinghua University | Lu X.,Key Laboratory of Civil Engineering Safety and Durability | And 2 more authors.
Earthquake Engineering and Engineering Vibration | Year: 2010

A "mega-earthquake" is one with an intensity larger than the most severe earthquake intensity category currently considered in design codes. For a "mega-earthquake," the design objective of a given structure is to "preserve living spaces for people in the buildings." In this paper, factors that may influence the collapse resistance of RC frames in a megaearthquake are analyzed based on seismic damage observed in the 2008 Wenchuan earthquake. Methodologies to improve structural collapse resistance focus on three aspects: global strength margin, global redundancy and global integration of the structural system. Fundamental principles and design concepts for collapse prevention under a mega-earthquake are proposed, and issues that need further research are identified. © 2010 Institute of Engineering Mechanics, China Earthquake Administration and Springer Berlin Heidelberg.


Zhou M.,Key Laboratory of Civil Engineering Safety and Durability | Zhou M.,Tsinghua University | Nie J.-G.,Key Laboratory of Civil Engineering Safety and Durability | Nie J.-G.,Tsinghua University | And 2 more authors.
Structures Congress 2013: Bridging Your Passion with Your Profession - Proceedings of the 2013 Structures Congress | Year: 2013

This paper investigates the implementation of multi-scale numerical method for the analysis of the complex mechanical behavior of the steel cable anchorage system in self-anchored suspension bridges. A multi-scale model of the Taohuayu Bridge (THY Bridge in brief), which is the largest self-anchored suspension bridge, is developed based on the design drawings of the actual bridge. The software ABAQUS was selected to realize the multi-scale finite element modeling of the THY Bridge for the purpose of wide applications in civil structures. An experimental scale model of the steel cable anchorage system was manipulated and tested based on the prototype of the THY Bridge to verify the multi-scale numerical model. Two elaborate FE models, including a scale model and a full-scale model, are established for comparison based on conventional elaborate modeling methods. Extensive comparison study of the test and various FE models demonstrate that fuzzy region exists in the results of the test model, scale model and full-scale model, and the fuzzy region cannot be quantitatively determined, leading to unreliable analysis results and enormous try and error works. By employing the flexible BCs, which is a kind of generalized boundary condition proposed in the paper, the multi-scale model can accurately predict the complex mechanical behavior of the cable anchorage system. The multi-scale modeling method may become a popular approach to investigate the cable anchorage system by modeling the entire self-anchored suspension bridge in the future. © 2013 American Society of Civil Engineers.


He M.-H.,Tsinghua University | He M.-H.,Key Laboratory of Civil Engineering Safety and Durability | He M.-H.,University of California at Berkeley | Xin K.-G.,Tsinghua University | Xin K.-G.,Key Laboratory of Civil Engineering Safety and Durability
Applied Mathematics and Mechanics (English Edition) | Year: 2011

An appropriate coupled cohesive law for predicting the mixed mode failure is established by combining normal separation and tangential separation of surfaces in the cohesive zone model (CZM) and the cohesive element method. The Xu-Needleman exponential cohesive law with the fully shear failure mechanism is one of the most popular models. Based on the proposed consistently coupled rule/principle, the Xu-Needleman law with the fully shear failure mechanism is proved to be a non-consistently coupled cohesive law by analyzing the surface separation work. It is shown that the Xu-Needleman law is only valid in the mixed mode fracture when the normal separation work equals the tangential separation work. Based on the consistently coupled principle and the modification of the Xu-Needleman law, a consistently coupled cohesive (CCC) law is given. It is shown that the proposed CCC law has already overcome the non-consistency defect of the Xu-Needleman law with great promise in mixed mode analyses. © 2011 Shanghai University and Springer-Verlag Berlin Heidelberg.


Zeng Q.,Tsinghua University | Zeng Q.,Key Laboratory of Civil Engineering Safety and Durability | Luo M.,Tsinghua University | Luo M.,Key Laboratory of Civil Engineering Safety and Durability | And 6 more authors.
Applied Surface Science | Year: 2013

This study investigates the surface fractal dimensions (SFDs) of pore structure of cement pastes and mortars with/without ground granulated blast-furnace slag (GGBS) incorporated into binder. The samples were subject to water curing and sealed curing. The fractal dimensions of samples are determined by Zhang's model (Ind Eng Chem Res, 34 (1995):1383-1386) on the basis of mercury intrusion porosimetry (MIP) data. The results confirm the scale-dependent property of fractal dimension of pore structures and the micro-fractal, transition and macro-fractal regions are identified for all samples. The upper pore size range for micro-fractal regions is around 30 nm, the transition regions cover 0.5-2 magnitude orders of pore size and macro fractal regions cover 1.5-3 magnitude orders. Both curing conditions and GGBS in binder have impact on the fractal properties of pore structure, and samples incorporating GGBS have substantially larger values for micro-fractal regions. © 2013 Elsevier B.V. All rights reserved.


Xu M.,Tsinghua University | Xu M.,Key Laboratory of Civil Engineering Safety and Durability | Chen J.-F.,Tsinghua University | Chen J.-F.,Key Laboratory of Civil Engineering Safety and Durability | And 2 more authors.
Yantu Lixue/Rock and Soil Mechanics | Year: 2010

The rapid development of infrastructure in the western area of China leads to the construction of more and more high fills. Accurate information on the shear behavior of the fill materials becomes a key issue for a safe design and construction. A series of large scale triaxial tests have been conducted on Douposi moderately-to-slightly weathered fill materials, which is a weak rockfill mainly found in Yunnan province. The test results show that the shear behavior of Douposi moderately-to-slightly weathered fill materials is very different from other typical rockfills, with a low shearing strength, while the stress-strain relationship, stiffness and strength characteristics are more similar to those of fine grain soils. Furthermore, water can reduce the strength of Douposi moderately-to-slightly weathered fill materials significantly, which must be taken into account during design and construction. Finally, it is demonstrated that the Duncan-Chang model is capable of simulating the shear behavior of Douposi moderately-to-slightly weathered fill materials.


Han L.-H.,Key Laboratory of Civil Engineering Safety and Durability | Li W.,Key Laboratory of Civil Engineering Safety and Durability
Journal of Constructional Steel Research | Year: 2010

The objective of this research is to investigate the seismic behaviour of the composite joint consisting of circular concrete filled steel tubular (CFST) column and steel beam with reinforced concrete (RC) slab. Six specimens, including four interior and two exterior joints, were tested under constant axially compressive load on the top of the columns and cyclic loads at the ends of the beams. The main experimental parameters were the type of the joint, the axial load level on the CFST column and the section configuration of the beam. Several indexes that could reflect the seismic behaviour of the composite joint, such as the ductility, the strength degradation, and the energy dissipation capacity were analyzed. It was found that the composite joints exhibited favorable seismic performance. © 2010 Elsevier Ltd. All rights reserved.

Loading Key Laboratory of Civil Engineering Safety and Durability collaborators
Loading Key Laboratory of Civil Engineering Safety and Durability collaborators