Shenzhen Municipal Design and Research Institute Co.

Shenzhen, China

Shenzhen Municipal Design and Research Institute Co.

Shenzhen, China
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Zheng C.,Jilin University | Zhao D.,Jilin University | Chen C.,Jilin University | Song Z.,Shenzhen Municipal Design and Research Institute Co. | Zheng S.,Jilin Provincial Communication Scientific Research Institute
Construction and Building Materials | Year: 2013

Quantitative test technology on the mesoscopic strength parameters of the mineral aggregate contact surface of bituminous-stabilized macadam was studied. On the basis of the failure mechanism of the mineral aggregate contact surface, the HC-40 hydraulic force measurement device and the self-designed test die were used to apply tensile load on the contact surface of the mineral aggregate. The total tensile strength Rt of the mineral aggregate contact surface was calculated. The total tensile strength Rt was compared with the splitting strength RT of the AM-20 Semi-Open-Graded bituminous-stabilized macadam mixture under different conditions. A corresponding calculation method was used to determine the adhesion strength Ra between the aggregates and bitumen, as well as the cohesion strength Rc of the bitumen binder itself. The results show that despite the small difference in numerical value between the total tensile strength Rt of the mineral aggregate contact surface and the splitting strength RT of the mixture, the variation law is consistent. The method of calculation adopted in the present study can provide the quantitative test for the adhesion strength Ra and the cohesion strength Rc at different states. The mesoscopic parameters of the mineral aggregate contact surface can directly affect the macroscopic strength parameters of the mixture. The test can promote the study on crack resistance and raveling resistance abilities of bituminous-stabilized macadam mixtures. Crown Copyright © 2012 Published by Elsevier Ltd. All rights reserved.


Yao G.,Shenzhen Municipal Design and Research Institute Co. | Yao G.,Tsinghua University | Li Y.,Fujian Agriculture and forestry University | Liao F.,Fujian Agriculture and forestry University
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2013

Based on rational constitutive models of steel and concrete, load-deformation relationship curves of concrete-filled steel tube (CFST) reinforced concrete columns subjected to axial compression were calculated by the fiber model method and finite element method to investigate the behavior of composite column subjected to axial compression. The results of theoretical analysis are in good agreement with the experimental ones. Based on the research conclusion mentioned above, behavior analysis of concrete-filled steel tube reinforced concrete columns subjected to axial compression including failure mode, axial load distribution, and the interaction between outer concrete, steel tube and core concrete were carried out. Practical simplified formulae of bearing capacity were proposed, and results calculated using the formulae agreed well with test results. At last, it is suggested that in order to ensure the collaborating between outer concrete and inner concrete filled steel tube, the ratio of stirrup constraint index in outer concrete to constraint effect coefficient in inner concrete filled steel tube should not be less than 0.188.


Zheng C.,Jilin University | Zhao D.,Jilin University | Xiang N.,Tongji University | Song Z.,Shenzhen Municipal Design and Research Institute Co.
Construction and Building Materials | Year: 2012

The low-temperature failure mechanism of mineral adhesion in asphalt mixtures with dense-suspension and void-skeleton gradations was investigated. Cylindrical-shaped minerals 60 mm in diameter and 55 mm high were split and then formed uneven surfaces that represented the amplified micro-surfaces of minerals. Based on the adhesion method of minerals in dense-suspension and void-skeleton structures, asphalt mineral powder sol slurry and a combination of fine aggregates were used to bond the specimen. Splitting tests were performed on the specimens at -30°C. The splitting strength was tested and the adhesion failure zone on the interface of damage was analyzed. Main and secondary adhesion zones were found to exist among the aggregates in the asphalt mixture with the dense-suspension structure. The adhesion failure among the aggregates simultaneously occurred in the secondary adhesion zone and in the combination body of the fine asphalt aggregates. There was no secondary adhesion zone in the asphalt mixture with the void-skeleton structure. The adhesion failure among aggregates occurred in the internal sol slurry of the asphalt mineral powder. At a low temperature, the adhesion failure zone of asphalt mixture aggregates had a close relationship with the type of mixture gradation. There were more adhesion failure zones in the asphalt mixture with the dense-suspension structure than in that with the void-skeleton structure. The lower splitting strength of the combination body of fine asphalt mineral powders may have caused the adhesion failure of the mineral aggregates. © 2012 Elsevier Ltd. All rights reserved.


Chen B.,Fuzhou University | Mu T.,Survey and Design Institute | Chen Y.,Shenzhen Municipal Design and Research Institute Co. | Huang J.,Fuzhou University
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2013

Steel-concrete composite structure is one of the main structures in civil engineering construction. In bridge engineering, composite members can be classified into three types according to the basic bearing behavior, i. e., composite beam, composite column and composite arch. In this paper, the main structure forms and general application of steel-concrete composite bridges in China are described; the research development and engineering application of the new composite structure types presented in recent years are focused on. The traditional steel-concrete composite bridges, such as the shaped steel-concrete slab composite girder, the PC box girder with corrugated steel webs and concrete filled steel tube arch, have been widely used and their specification system has been established by far. In the future, the application experience should be constantly summed up so as to further improve the specifications. At the same time, it is necessary to track closely the latest international trends and carry out innovative research. The research and development of new composite bridge have become very active in our country in recent years. Many new types of steel-concrete composite bridge structures were developed, such as the deck slab with stiffened scaffolding and CFST composite truss, corrugated steel web-CFST composite beam, CFST stiffened scaffolding composite columns, CFST main members with reinforced connection members composite columns and hybrid columns and steel webs (bars)-concrete arch bridge. Some of them have been used in few engineering projects, while others have not been used. In the future, it is important to strengthen their application and popularization, conduct application technology research on the engineering practice requirement, form application guide or technical standards, and make contribution to the development of the composite structures and technical progress of bridge engineering.


Fu Y.,Hunan University | Zhang P.,Hunan University | Yang F.,Shenzhen Municipal Design and Research Institute Co.
Materials and Design | Year: 2010

Various functionally graded design methods have been proposed recently for fiber reinforced composite plates. The laminates with variable fiber spacing along the thickness direction are focused on in this paper. Fiber volume ratio distribution functions are defined separately in each single layer. Classic state space method as well as differential quadrature state space method are utilized here for different boundary and plied conditions. For the latter method, a sub-layer based scheme, which has both high accuracy and less numerical capacity, is suggested for functionally graded plates. Numerical examples indicate that the non-uniform distribution of fibers rearranges the stress field, of which the in-plane stresses are sensitive to the fibers' distribution, while the transverse stresses are not affected so much. In-plane stresses near interfaces would decrease if the fiber ratio reduces in this region, which provides a method to resolve the interfacial stress concentration problems. © 2009 Elsevier Ltd. All rights reserved.


He J.,Tongji University | Liu Y.,Tongji University | Chen A.,Tongji University | Dai L.,Shenzhen Municipal Design and Research Institute Co.
Construction and Building Materials | Year: 2012

This paper proposed a novel cost-effective movable hybrid GFRP and concrete deck consisting of corrugated pultruded GFRP plate with T-upstands for the tension part and concrete with reinforcing bars for the compression part. First, the strength and stiffness of GFRP plate serving as formworks for concrete casting under construction stage was verified by sand filling test. Then, static tests on six full-scale models with different penetrating bars and surface treatment under sagging moments were conducted to evaluate the load-carrying capacity and failure modes of proposed hybrid deck. The load and displacement relationship, ultimate flexural resistance, strain distribution on GFRP plate and concrete slab were measured during the test. Experimental results indicated that both surface treatment and penetrating bars improve the connection between GFRP plate and concrete, and promote the ultimate strength and rigidity of hybrid deck. In addition, the concrete used for encasing corrugated pultruded GFRP plates not only increases its stiffness, but also prevents local buckling failure of the GFRP plate with T-upstands. The comparison of experimental and theoretical ultimate strength results showed ACI 440 flexure and shear equation can effectively predict the ultimate capacity for the hybrid deck. The overall investigation showed the presented hybrid GFRP and concrete concept is a better alternative for beam-and-slab bridges. © 2011 Elsevier Ltd. All rights reserved.


Shi X.-S.,University of Sichuan | Wang Q.-Y.,University of Sichuan | Ouyang W.-X.,University of Sichuan | Chen Y.-Y.,Shenzhen Municipal Design and Research Institute Co.
Gongcheng Lixue/Engineering Mechanics | Year: 2012

PBL shear connector is a key structure as the connection of corrugated web and flange up and down in composite bridges. The bond-slip behavior of PBL connector is significantly important for connector design. In this paper, the development of PBL shear connector is presented, and four PBL shear connector push-out tests under static loadings are conducted based on its practical application in pre-stressed concrete box-girder with corrugated steel web, in such a way the influence of the web's thickness and the hole's dimension is investigated on the bond-slip behavior, ultimate bearing capacity and failure mechanism. The results show that, every specimen shows similar bond-slip trend and ductility; thicker web and bigger diameter of the hole yield greater ultimate bearing capacity. Meanwhile, the relationship between the load and horizontal displacement shows that, during the preliminary loading stage, the concrete slabs expand outwards under the transferred shear load, and then distinct slip happens to shear connectors and the concrete slabs move outwards a little with the load increasing. The strain development accords with the load transformation rules from the records of strain gauges on the web, the flange of shear connectors and the steel slab. Finally, the experimental and analytical results are compared and the main influence factors on the ultimate capacity are presented, as a result, a new formula is proposed.


Qiao L.-P.,Shenzhen Municipal Design and Research Institute Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2012

Based on the engineering application of soil nailing of steel tube in an excavation with deep filling soils, the characteristics of the excavation, the procedures of design and calculation and the attentive aspects are introduced. How to reasonably choose the shear intensity parameters c and ψ of the filling soils and the friction of the nail-soil in the design and calculation and the ways to judge the years of the filling soils, are discussed. At the same time, the production technology of the soil nailing of steel tube and the quality of the jet grouting, which are the key to successful excavation bracings, are emphasized. The ideas of how to choose the design parameters and the requirements of construction technology may offer reference for similar excavation projects.


Zou G.,Shenzhen Municipal Design and Research Institute Co.
Chinese Journal of Environmental Engineering | Year: 2014

The performance of the dual-intake reversed A2/O-MBR System(hereinafter referred to as the "system") processing municipal wastewater was evaluated by inspecting indicators such as COD, NH4 +-N, TN, TP and SS. Results show that the system had high COD and NH4 +-N removal rates, the effluent COD and NH4 +-N confirmed to one-class a permitted criteria of the GB18918-2002. The effluent TN concentration was under 15 mg/L when the mixed liquor reflux ratio reached 200%. The system TP removal rate reached about 83% under normal excess sludge discharge operation. The effluent SS and COD could be affected by damaged flat-sheet membrane. COD, TP and SS can be intercepted directly by the membrane system and due to the nearly 100% solid retention, the system SRT can be controlled properly to in favor of the growth of long life-cycle microorganisms such as nitrifying bacteria and denitrifying bacteria. Thanks to the good solid retention effect, the system effluent can still be good with sludge concentration up to 15000 mg/L even influent increased by 50%.


Yu H.-Z.,Shenzhen Municipal Design and Research Institute Co. | Ouyang Y.-F.,Shenzhen Municipal Design and Research Institute Co. | Chen H.,Shenzhen Municipal Design and Research Institute Co.
2012 14th International Conference on Ground Penetrating Radar, GPR 2012 | Year: 2012

The main constructing methods of metro tunnel include shield tunneling method (TBM) and mining method. The quality of the tunnel constructed by mining method is less stable than by TBM. Various faults may occur during the construction. The tunnel should be inspected by reliable inspecting methods. The inspecting practices in Shenzhen metro indicate that ground penetrating radar (GPR) can be used to exactly inspect the thickness of the second lining, the rebar distribution within the second lining, the dense of the second lining concrete, the cave distribution behind the second lining and so on. ©2012 IEEE.

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