Beijing Building Construction Research Institute

Beijing, China

Beijing Building Construction Research Institute

Beijing, China
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Liu H.,Beijing Building Construction Research Institute | Lan C.,Beijing Building Construction Research Institute | Lan C.,Beijing Jiaotong University | Yang X.,Beijing Building Construction Research Institute
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2015

The seismic retrofitting method of clay brick masonry structure using vertical post-tensioning tendons is developed to improve the poor seismic performance of the structure. By arranging the post-tensioning tendons uniformly along the wall and applying vertical prestressing, the brick wall is under uniform compression, thus the failure pattern of the masonry walls is improved and the shear capacity and the energy dissipating ability are also improved. The effectiveness of this method was investigated experimentally through quasi-static test of nine unreinforced masonry walls, including five walls without opening and four walls with opening. The failure pattern and the mechanical behavior of the unretrofitted walls and the retrofitted walls were analyzed and compared. The results show that post-tensioning can increase the shear capacity and the deformability substantially, and the seismic energy dissipating ability is also significantly increased. And the improvement of the shear capacity and the ductility of the walls without opening is more significant than that of the walls with opening.However, the axial force due to the addition of prestressing force and vertical load shouldn't exceed a certain limit, otherwise the ductility will decrease in some degree. Moreover, the lateral stiffness degradation speed of the wall retrofitted with post-tensioning tendons can be slowed down and after cracking stiffness can be improved, which may be very helpful to the mechanical behavior of the wall under a severe earthquake. In addition, the elastic stiffness and the weight of the brick wall are hardly changed due to the retrofitting method, which shows that the retrofitting method using vertical post-tensioning tendons is an effective and reliable strengthening alternative for unreinforced masonry structures. ©, 2015, Science Press. All right reserved.


Shi G.,Tsinghua University | Fan H.,CITIC General Institute of Architectural Design and Research Co. | Bai Y.,Monash University | Zheng J.,Beijing Building Construction Research Institute
Proceedings of the Institution of Civil Engineers: Structures and Buildings | Year: 2015

Damage such as cable pre-stress loss and anchorage failure may occur in a glass curtain wall structure supported by single-layer plane cable net but the influence on overall structural responses has not yet been identified. A finiteelement model considering the stiffness contribution from glass panels is established to study the effects of two forms of damage: pre-stress loss and anchorage failure. The accuracy and reliability of the numerical model are validated experimentally, and the effects of stiffness of the glass panel on stress distributions are discussed. Compared to experimental results, the finite-element model has sufficient accuracy to quantify the damage effects. The contribution from bending stiffness of glass panels to overall structural stiffness is identified as about 10.6% and that from the glass panel membrane effect is about 12.2%. The modelling approach is extended to describe a realistic 15 × 3 15 m glass curtain wall structure. The corresponding parametric analysis demonstrates that the stiffness contribution from glass panels depends on certain design parameters (e.g. number of glass grids and overall span), but can be ignored for structures with more than ten grids. In the investigated structures with 6~15 grids, almost no difference was found between the effects of damage on the glass curtain wall structure and on the pure supporting cable net structure. © ICE Publishing: All rights reserved.


Yin H.-Y.,Sichuan University | Wei X.-F.,Sichuan University | Bao R.-Y.,Sichuan University | Dong Q.-X.,Beijing Building Construction Research Institute | And 4 more authors.
CrystEngComm | Year: 2015

Even though self-nucleation is considered to be the ideal case for polymer nucleation, it has rarely been used to enhance polymer crystallization in practical processing techniques. Inspired by self-nucleation theory and by utilizing the large difference in melting points of various poly(l-lactide) (PLLA) resins, we introduced high-melting-point PLLA (hPLLA) crystallites into a low-melting-point PLLA (lPLLA) matrix via melt blending at a processing temperature between the two melting points of the selected PLLA resins. The hPLLA crystallites turn out to be efficient nucleating agents (NAs) for lPLLA and high crystallinity (>40%) PLLA samples with a greatly accelerated crystallization rate can be easily obtained. The results of non-isothermal crystallization show that the crystallization process is remarkably accelerated with a small amount (0.1 wt%) of hPLLA. With a further increase of hPLLA content, the crystallization temperature of the blends continues to shift to higher temperature. This crystallization promoting effect results from the excellent nucleation ability of the hPLLA crystallites, as revealed by in situ optical microscopy observation. Furthermore, an incredibly high nucleation efficiency of 103.0% (exceeding 100%) was obtained for the PLLA sample with 5.0 wt% hPLLA. The nucleation mechanism for hPLLA was studied systematically. It was found that the lPLLA matrix and hPLLA crystallites possess an absolutely identical crystal structure of α-form crystals and an excellent interfacial interaction between the nucleating agent, i.e., hPLLA crystallite, and the lPLLA matrix is achieved, resulting in the reduction of the energy barrier for heterogeneous nucleation and acceleration of crystallization kinetics. Therefore, by using high-melting-point polymer crystals as NAs, the crystallization rate of their low-melting-point polymer matrix can be improved largely, thus providing a simple way to obtain high crystallinity products for semicrystalline polymers with very low crystallization rates. This journal is © The Royal Society of Chemistry 2015.


Shi G.,Tsinghua University | Zuo Y.-Z.,Beijing Building Construction Research Institute | Zheng J.-J.,Beijing Building Construction Research Institute | Shi Y.-J.,Tsinghua University | Wang Y.-Q.,Tsinghua University
Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics | Year: 2011

Three-dimensional finite element models are developed by using the general-purpose finite element software ANSYS, to simulate and analyze the static behavior of single-layer plane cable net with different damages, including failure of connectors between horizontal cables and vertical cables, the cable prestress loss, failure of the cable anchor end, and the corresponding tests are carried out to validate the finite element model. The results indicate that this finite element model is able to accurately analyze the influence of the above-mentioned three damages on the static behavior of the single-layer plane cable net, including the structural deformation and the distribution of cable forces. And this finite element model can also accurately take into account the effect of the location and extent of each damage, correctly reflect the situation of the structural damages. Hence it can be applied for further finite element parametric analysis on the single-layer plane cable net with different damage characteristics and structural characteristics, based on which the reliable structural safety analysis model and method can be established.


Shi G.,Tsinghua University | Zuo Y.,Beijing Building Construction Research Institute | Shi X.,University of Glasgow | Shi Y.,Tsinghua University | And 2 more authors.
Frontiers of Architecture and Civil Engineering in China | Year: 2010

The single-layer cable net supported glass curtain wall has been applied in many building structures all over the world. In service, it will inevitably be subject to various damages. To study the influence of such damages on the static behavior of the single-layer cable net supported glass curtain wall, a full-scale model with the outside outline size of 4. 85 m × 4.85 m and 4 × 4 grids is designed and tested. Two kinds of damages that are the cable prestress loss and cable anchorage end failure are led into the structure model during the test, and their influence has been investigated. The stiffness contribution of glass panels to the single-layer cable net supported glass curtain wall structure with or without damages and its change have been tested and analyzed. The results show that the maximum change rate of nodal deflection is 13.78% for the damage of cable prestress loss, while the change rate of nodal deflection is between 7% and 22% for the damage of cable anchorage end failure. The influence degree of the damages depends on the ratio of the structure initial stress stiffness change caused by damages to the total stiffness of the structure. The stiffness contribution of glass panels increases with the load increase. Under the same loading condition, the stiffness contribution of glass panels to the damaged structure is greater than that to the intact structure. The stiffness contribution of glass panels reduces the effect of the damages on the structural displacement and the cable tension force, but the glass panel could break if its stiffness contribution is too large. © 2010 Higher Education Press and Springer-Verlag Berlin Heidelberg.


Shi G.,Tsinghua University | Zuo Y.,Beijing Building Construction Research Institute | Zheng J.,Beijing Building Construction Research Institute | Huo D.,Beijing University of Technology
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2010

During the service of single-layer plane cable net supported glass buildings, as the supporting structure the single-layer plane cable net will inevitably be subjected to different types of damages. In order to study the influence of such damages on the static behavior of the single-layer plane cable net, a full-scale model with the dimension of 4.85 m × 4.85 m and 4 × 4 grids was designed and constructed. Static tests were conducted after introducing three types of damages including failure of connectors between horizontal and vertical cables, cable prestress loss and cable anchorage failure. The results indicate that, failure of connectors between horizontal and vertical cables almost has no influence on the static behavior of the single-layer plane cable net; the change of nodal displacements induced by the cable prestress loss does not exceed 15%; the cable anchorage failure affects the local part of the single-layer plane cable net significantly, and the induced change of nodal displacements is between 18% and 36%; damages have stronger effect on nodal displacements than cable tension forces. The intensity of the influence of damages depends on the damage degree and location, and decreases with the increase of load. The research results provide a sound foundation for establishing the safety evaluating method of in-service single-layer plane cable net structures.


Lan C.,Beijing Building Construction Research Institute | Lan C.,Beijing Jiaotong University | Liu H.,Beijing Building Construction Research Institute | Zhou Z.,Dalian University of Technology
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2013

Prestress loss is critical to the safety of prestressed structures. Unfortunately, nowadays, there are no qualified techniques to treat with this issue due to the fact that monitoring sensors may not survive the harsh construction environments and the time-dependent service life of the large-span prestressed structures. In this study, a novel smart steel strand based on the technique of integrating the Brillouin with fiber Bragg gratings (FBG) signal was introduced. Two kinds of prestressed PC beams were used to verify the idea of monitoring prestress loss by using smart steel strands. The prestress loss data may be achieved by Brillouin and FBG sensors, respectively, and then the data were compared with those from conventional sensors. It was shown that the monitored data can reveal the entire process of prestress loss in the construction stage and service life, and the data agree well with those from the structural analysis and provide higher accuracy than the data from conventional sensors, indicating that such kind of smart steel strands may be conveniently used to monitor the prestressed reinforcement in prestressed concrete structures.


Zhang T.,Beijing University of Technology | Zuo Y.Z.,Beijing Building Construction Research Institute | Teng H.W.,Beijing University of Technology | Ma D.Y.,Beijing Building Construction Research Institute | Liu H.,Beijing University of Technology
Applied Mechanics and Materials | Year: 2014

Damping ratio is a very important parameter for building structures in the analysis of dynamic response. Story-adding RC structure of light-weight steel is composed by two different material stories. If all the modal damping ratios are defined as the same, as to the dynamic analysis for that structure, the results of analysis will be inappropriate. This paper made some response spectrum analysis on a six-story story-adding RC structure of light-weight steel by finite element analysis software Midas Gen through defining the Rayleigh damping. In the meanwhile, compared the results based on different Rayleigh damping parameters with the results by using the method of strain energy proportional, and got the rule of the definition of Rayleigh damping. © (2014) Trans Tech Publications, Switzerland.


Liu M.,Shenyang Jianzhu University | Fan X.-H.,Technology Center | Zuo Y.-Z.,Beijing Building Construction Research Institute | Song B.-F.,Shenyang Jianzhu University
Advanced Materials Research | Year: 2013

The reinforcement project is three-storey of the industries building, the total height of the industries building is 14,200mm, the clear height of one storey is 7,500mm, the building area is 1,500 square meters, structural mode is reinforced concrete frame structure. The structural members were damaged seriously due to fire In January 2010, strengthening the damaged members was proposed in order to ensure the safety of the structure. Enlarging section reinforcement method, Polymer Mortar and gluing CFRP methods were adopt to strengthen the beams, columns and floor slab depending on the damage degree of the concrete member.The idea of dealing with the industries building damaged by fire can provide us a good reference of repairing the similar industries building. © (2013) Trans Tech Publications, Switzerland.


Liu Z.,Beijing Building Construction Research Institute | Xu R.,Beijing Building Construction Research Institute
Advanced Materials Research | Year: 2011

There have been few researches on the reliability of prestressed steel structure, especially the study on the reliability considering the failure of key components. In order to study the impact of the component failure on the structure reliability, the response surface method based on central composite design is adopted and APDL language is applied to write a corresponding program, thereby carrying out reliability calculation and analysis to the model. The system reliability and parameters sensitivity of the beam string structure under different failure of components are provided. The results indicate that the impact of cable failure on the reliability is large, but it is weak by the failure of brace rod. The results may serve as a reference for the health monitoring and safety assessment of the prestressed steel structure. © (2011) Trans Tech Publications.

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