China Construction Seventh Engineering Division Co.

Zhengzhou, China

China Construction Seventh Engineering Division Co.

Zhengzhou, China
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Jiao A.,Chongqing University | Jiao A.,China Construction Seventh Engineering Division Co. | Zhang P.,China Construction Seventh Engineering Division Co. | Li Y.,China Construction Seventh Engineering Division Co. | Zhi X.,Harbin Institute of Technology
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2015

In order to study the seismic behavior of pre-cast reinforced concrete(RC) shear walls with annular closed reinforcements, quasi-static tests of 15 shear wall specimens were carried out. Influence of styles of connection, arrangements of reinforcement and axial compression ratios on bearing capacity, hysteretic characteristics and failure mechanism were studied. According to the diameter of vertical reinforcements and strength grade of concrete, the specimens were divided into three groups. Each group included two cast-in-situ RC wall specimens and three pre-cast wall specimens. The test results indicate that the failure mode of pre-cast wall specimens is the same as that of cast-in-situ wall specimens, i.e., compression-bending mode. The ultimate drift ratios of the pre-cast wall specimens with annular closed reinforcements are 1/82~1/50, and the ultimate lateral bearing capacity, energy-dissipation and ductility performance of them are similar to that of cast-in-situ RC wall specimens. Research shows that pre-cast reinforced concrete shear walls with annular closed reinforcements have good seismic performance and they can be used for prefabricated shear wall structures. ©, 2015, Science Press. All right reserved.


Ding W.,Luoyang Institute of Science and Technology | Xu T.,China Construction Seventh Engineering Division Co. | Wang H.,Luoyang Institute of Science and Technology | Chen J.,Institute of Longmen Grottoes
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2015

Mechanical experiments of the limestone samples from Longmen grottoes under the action of coupled chemical solutions and freezing-thawing processes were carried out to investigate the infiltrated water erosion and freezing-thawing damage on the surrounding rocks in Longmen grottoes. The results of the experiments demonstrated that the mechanical damage of limestone was increased gradually as with increasing freezing- thawing cycles under the coupled chemical solution and freezing-thawing processes and the damage was greater than that under the erosion of chemical solutions only. For example, for the cases of the freezing-thawing cycles of 90 under the coupled chemical solution and freezing-thawing processes, the strengths of the specimens soaked in the distilled water, Longmen water and NaCl solution dropped 50.73%, 54.92% and 57.67% respectively compared with the specimen strength in the natural state. While under the erosion of chemical solutions without freezing-thawing, the strengths was dropped only 21.58%, 22.88% and 28.72% respectively. The freezing-thawing deterioration model of limestone under investigation was found to be all due to the particle loss model. The abundance of the condensation nuclei and the pH value of water solution were found to be the important factors affecting the degree of damage to the limestone under the coupled chemical solution and freezing-thawing processes. An equation describing the erosion damage to limestone under coupled action was established. ©, 2015, Academia Sinica. All right reserved.


Ding W.-X.,Luoyang Institute of Science and Technology | Chen J.-P.,Institute of Longmen Grottoes | Xu T.,China Construction Seventh Engineering Division Co. | Chen H.-J.,Luoyang Institute of Science and Technology | Wang H.-Y.,Luoyang Institute of Science and Technology
Yantu Lixue/Rock and Soil Mechanics | Year: 2015

To explore the chemical erosion phenomena, the chemical compositions of the spring water, seeping water and rainwater in Longmen Grottoes area are analyzed; and chemical solutions with different compositions are artificially made, which are in turn used to study the mechanical properties and the chemical solubility of Longmen Grottoes limestone under influences of different chemical solutions. The strength damage characteristics of the limestone are obtained based on the mechanical experiments with respect to different solutions and different erosion durations. A time-dependent corrosion equation of uniaxial compressive strength for limestone is developed under different chemical solutions. Based on the chemical kinetic tests on limestone under the effects of the different chemical solutions and for different erosion durations, the solubility of limestone eroded by different chemical solutions is addressed. The chemical dynamic erosion equations of limestone are developed. The analysis indicates that the strength of limestone decreases due to the dissolution of chemical solutions under chemical erosion. The salt effect and the common ion effect significantly influence the dissolution rate and strength of limestone. The salt effect can raise the dissolution rate, while the common ion effect can reduce the dissolution rate. When the composition and concentration of the solution are the same, the stronger the acidity, the larger the dissolution rate is. The dissolution rate of limestone increases with the increase of salt concentration when the composition and the pH value of the solution are the same. ©, 2015, Academia Sinica. All right reserved.


Li Z.,Chongqing University | Xu S.,Chongqing University | Liu H.,Chongqing University | Jiao A.,Chongqing University | Jiao A.,China Construction Seventh Engineering Division Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2016

By combining the advantages of precast buildings with the advantages of concrete filled steel tubular (CFST) column-reinforced concrete (RC) beam braced frames, a new type of precast CFST column-RC beam braced frame structure with welded and bolted steel connections is proposed. In a series of shake table tests with a variety of earthquake intensities, a 1:3 scale 6-story model was excited for investigating the structural dynamic response, failure pattern, global seismic performance, structural failure path and reliability of connection joints of this type of structure. The study shows that: (1) This type of structure exhibits "strong CFST column-weak RC beam" and "strong connection-weak member" failure mechanisms; (2) Damages generally occur at the interface between the reinforced concrete beam segment and the I-section steel girder segment with a considerable distance to the core area of the beam-column joint, so that the integrity of the core area of beam-column joint can be ensured; (3) Due to the failure of braces under strong earthquake action, a few floors can be transformed into weak stories, leading to the amplification of the structural dynamic response. © 2016, Editorial Office of China Civil Engineering Journal. All right reserved.


Jiao A.,Chongqing University | Jiao A.,China Construction Seventh Engineering Division Co. | Li Z.,Chongqing University | Liu H.,Chongqing University | Mao J.,Chongqing University
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2014

A new analytical model as well as computational method to calculate rotational deformation of K-type joints consideration semi-rigid connections in UHV transmission tower is presented based on full-scale tests of K-type joint. This method can make a good performance in calculating and analyzing the different component related to rotational deformation, including the shear deformation of the main angle-steel, the shear deformation of bolt and the deformation of bolt. It is considered that the connection rotation is mainly induced by the deformation of the main angle in shear, bolts in shear, hole wall in bearing and it provides the moment-shear rotation curve and moment-rotation curve. The three parameter power function model of Kishi-Chen is suitable for this kind of joint moment rotation calculation, resulting in shape coefficient of approximately between 1.5~2.2. The proposed model quantifies effects on initial rotational stiffness of limb width and thickness, bolt diameter and joint plate thickness, but cannot consider the two limbs boundary interaction of angel-steel.


Jiao A.-L.,Chongqing University | Jiao A.-L.,China Construction Seventh Engineering Division Co. | Li Z.-L.,Chongqing University | Liu H.-J.,Chongqing University
Applied Mechanics and Materials | Year: 2014

Both experimental research and theoretical analysis of ultimate strength for steel tubular tower joint are developed. The experimental data comprise four different specifications of steel tube, that is, without ribbed plate, with 1/4 annular ribbed plate, with 1/2 annular ribbed plate and with annular ribbed plate. This paper considers that the ultimate strength of steel tubular joint depend on the following four parameters, that is, the ratio of length of joint plate to outer diameter of steel tube B/D, outer diameter D, axial force and ratio of length of annular plate to outer diameter of steel tube R/D as well as the ratio of thickness of annular plate to thickness of steel tube. Furthermore, a recommended formula of the ultimate strength of steel tubular joint is derived by the potential energy principle and the principle of virtual work in elasticity and plasticity based on the failure modes of experimental specimens. It is demonstrated that the applicability of the recommended formula is better. © (2014) Trans Tech Publications, Switzerland.


Xu S.,Chongqing University | Li Z.,Chongqing University | Liu H.,Chongqing University | Jiang J.,Chongqing University | And 2 more authors.
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2016

Combining the advantages of precast connections and concrete filled steel tubular (CFST) column to reinforced concrete (RC) beam connections, a stiffened precast sleeve-connected CFST column to RC beam connection was proposed. Considering axial compression ratio, connected angle and location of the connection, pseudo-static experiments were conducted to investigate the earthquake resistance of the connections, whose failure mode, failure mechanism, hysterical behavior, envelop curve, ductility and energy-dissipating capacity were analyzed. Fine finite element models were built and verified by ABAQUS. The results show that: this type of connection could exhibit “strong CFST column-weak RC beam” and “strong connection-weak member” failure mechanisms and have excellent load carrying capacity, specimens fail due to the fracture of longitudinal reinforcement up until vertical displacement of beam-end reaches to 3-4.5 times of yield displacement; this type of connection also has excellent energy dissipating capacity and ductility, ductility coefficients of the connections with a 45 degree connected angle and 90 degree connected angle are respectively greater than 3 and 4. © 2016, Editorial Board of Journal of Harbin Institute of Technology. All right reserved.

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