Beijing Wanke Co.

Beijing, China

Beijing Wanke Co.

Beijing, China
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Qian J.,Tsinghua University | Han W.,Tsinghua University | Zhao Z.,Tsinghua University | Qin H.,Beijing Wanke Co. | And 4 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2017

To study the seismic behavior of the prefabricated concrete shear wall structure with rebars splicing by grout sleeves, pseudo-dynamic substructure test on a 3-story full-scale model was performed under the excitation of earthquake record. The cracks and damage phenomena of the test model were observed. Further analysis was conducted to investigate the seismic behavior, such as the hysteretic characteristic, deformation capacity, stiffness degradation and rebar yield order.The results indicate that cracks and damage of the test model center on the coupling beams and the window belly walls in the earthquake excitation direction, characterized by bending failure in the coupling beams, shear failure in the window belly walls and slight bending failure in the wall piers.The longitudinal rebars of coupling beams, the vertical rebars of wall piers and the stirrups of coupling beams yield in turn, which indicates that the design concepts `strong wall pier, weak coupling beam' and `strong shear, weak bending' of coupling beam are achieved.Under frequent earthquake, design earthquake and rare earthquake of seismic fortification intensities eight, and rare earthquake of seismic fortification intensity nine, the lateral stiffness of the test model decreases about 5%, 20%, 60% and 80%, respectively, compared with the initial stiffness. The maximum inter-story drift ratios are 1/3 341, 1/899, 1/268 and 1/111 respectively under the same load conditions, which shows that the damage extent of the test model is no damage, slight damage, moderate damage and collapse, respectively.Since the concrete superposition two-way floor slabs with rebars or no rebar protruding from precast bottom slab both are of good integrity and adequate in-plane stiffness, both types of superposition floor slab can be considered as a rigid diaphragm. It is feasible by using two U-shaped rebars to form a closed stirrup instead of the ordinary stirrup in the rectangular vertical post-casting section between two precast shear walls. The connection between inner wythe and outer wythe of the precast concrete sandwich insulation wall is reliable. As the outer wythe does not participate in bearing loads, the contribution of the outer wythe can be neglected in the structural design. © 2017, Editorial Office of Journal of Building Structures. All right reserved.


Qian J.,Tsinghua University | Yang X.,Beijing Wanke Co. | Qin H.,Beijing Wanke Co. | Peng Y.,Tsinghua University | And 2 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011

Quasi-static tests of five reinforced concrete shear wall specimens with aspect ratio of 2.25 are introduced in this paper. Among the five specimens, one was cast-in-place wall specimen, and other four were pre-cast wall specimens with different methods of vertical reinforcement splicing. The test results indicate that the failure mode of the pre-cast wall specimens is the same as that of the cast-in-place wall specimen, i.e., tensile yield of the vertical reinforcements in the boundary elements and compressive failure of concrete at the wall bottom. The sleeve-mortar splicing transfers stresses of vertical reinforcement effectively. The specimen with stirrup splicing has in-plane slide between the pre-cast wall and the cast-in-place part, which has the minimum values of ultimate drift ratio and energy dissipation capacity among the five specimens. The ultimate drift ratios of all specimens are larger than 1/100. The measured compression-flexural strength of the pre-cast wall specimens are larger than the current code calculated value. Based on the test results, recommendations on further studies of pre-cast shear walls are proposed.


Qian J.,Tsinghua University | Hu Y.,Tsinghua University | Zhao Z.,Tsinghua University | Feng S.,Tsinghua University | And 4 more authors.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2014

The assembled monolithic coupling beam is composed of a precast upper wall segment, a cast-in-place segment and a precast lower wall segment. To study the seismic behavior of assembled monolithic coupling beams, quasi-static tests on 9 coupling beam specimens with 5 different span-to-height ratios were carried out. Among the beam specimens, four specimens employed reinforced connecting sleeves with grout to splice the precast lower wall segment and the cast-in-place segment, four specimens had no splice of reinforcements between the precast lower wall segment and the cast-in-place segment, and one specimen was composed of the precast upper wall segment and the cast-in-place segment. The test results indicated that the coupling beams failed in the bending mode, the interface between the coupling beam and the wall cracked, and the concrete at two ends or corners of the coupling beam crushed with flexural cracks and diagonal cracks distributed all over the coupling beam surface. For those specimens without splicing between the precast lower wall segment and the cast-in-place segment, the precast lower wall segment separated from the cast-in-place segment, leading to two individual coupling beams. The hysteretic curves of moment-rotation hysteretic loops exhibited the pinching effect to a certain degree. The ultimate rotations (average values of positive and negative loads) varied within 1/24~1/60, exhibiting a good elastic-plastic deformation capability. The ultimate rotations of coupling beams with a span-to-height ratio of 1.5 were smaller than those of the same type of coupling beams with the span-to-height ratio as 2.0 or 2.4. In addition, the flexural capacity of assembled monolithic coupling beams can be calculated according to the current standard formulas for monolithic coupling beams, and moreover, whether splicing the precast lower wall segment and the cast-in-place segment or not had no significant impact on the bearing capacity and hysteretic behavior of coupling beams.


Zhang W.,Beijing University of Technology | Qian J.,Tsinghua University | Yu J.,Beijing University of Technology | Qin H.,Beijing Wanke Co. | Liu G.,Beijing Wanke Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2012

To further study the seismic behavior of precast reinforced concrete shear walls in which the vertically distributed reinforcements are indirectly connected with a single row of rebars spliced by grouted straight-thread couplers, quasi-static tests are carried out for five specimens with cast-in-situ boundary elements. Three specimens have cast-in-situ boundary element at one end, while the others have cast-in-situ boundary element at both ends. The test results indicate that the cast-in-situ boundary elements and the precast shear wall work together as one unit, horizontal cracks and extended diagonal cracks are the main cracks of the specimens, horizontal cracks run through the interface between the wall and the base beam, vertical rebars yield before the specimen reaches its strength, and the concrete crushes at the bottom of the wall. All specimens fail in compression-bending mode. The ultimate drift ratios of specimens are 1/99~1/62. The current code formulas are suitable for calculating the compression-bending strength of precast shear walls, and the contribution of vertical distributed reinforcements should be taken into consideration.


Zhang W.,Beijing University of Technology | Jiang X.,Beijing University of Technology | Zhang B.,Beijing University of Technology | Qin H.,Beijing Wanke Co. | Zhang Y.,Beijing Wanke Co.
World Information on Earthquake Engineering | Year: 2013

To investigate the seismic behavior of assembly integrated coupling beams, quasi-static tests of 2 two-story assembly integrated coupled shear walls were performed. The geometrical sizes of the two specimens are same and the reinforcements are basically same, the differences lie in the connection mode among the window wall of the first floor, post-poured strip and the spandrel under the window of the second floor, Specimen A adopts single row of grout sleeves splices while there is no in specimen B. The test results indicate that the failure mode of the 2 specimens is same, the ends of coupling beams formed plastic hinges, the main damage is bending destruction, there is relative sliding between the post-poured strip of the coupling beam and the spandrel under the window of the second floor, there are shear skew cracks at the whole coupling beams of specimens. The bearing capacity and stiffness of the 2 specimens are basically same, the ultimate drift ratios are greater than 1 /90.For the assembly integrated coupling beam with or without reinforcements grout sleeves splices, its seismic behavior meets the requirements.

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