A simplified seismic design method for low-rise dual frame-steel plate shear wall structures

Jiulin Bai,Jianyuan Zhang,Ke Du,Shuangshuang Jin 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.37 No.4

In this paper, a simplified seismic design method for low-rise dual frame-steel plate shear wall (SPSW) structures is proposed in the framework of performance-based seismic design. The dynamic response of a low-rise structure is mainly dominated by the first-mode and the structural system can be simplified to an equivalent single degree-of-freedom (SDOF) oscillator. The dual frame-SPSW structure was decomposed into a frame system and a SPSW system and they were simplified to an equivalent F-SDOF (SDOF for frame) oscillator and an equivalent S-SDOF (SDOF for SPSW) oscillator, respectively. The analytical models of F-SDOF and S-SDOF oscillators were constructed based on the OpenSees platform. The equivalent SDOF oscillator (D-SDOF, dual SDOF) for the frame-SPSW system was developed by combining the F-SDOF and S-SDOF oscillators in parallel. By employing the lateral force resistance coefficients and seismic demands of D-SDOF oscillator, the design approach of SPSW systems was developed. A 7-story frame-SPSW system was adopted to verify the feasibility and demonstrate the design process of the simplified method. The results also show the seismic demands derived by the equivalent dual SDOF oscillator have a good consistence with that by the frame-SPSW structure.

Integrating of Nonlinear Shear Models into Fiber Element for Modeling Seismic Behavior of Reinforced Concrete Coupling Beams, Wall Piers, and Overall Coupled Wall Systems

Ke Du,Huan Luo,Jiulin Bai,Jingjiang Sun 한국콘크리트학회 2019 International Journal of Concrete Structures and M Vol.13 No.5

Reinforced concrete (RC) coupled wall systems, compared with RC shear wall without opening, have more com-plex nonlinear behavior under the extreme earthquake loads due to the existence of coupling beams. The behavior characteristics induced by nonlinear shear deformation such as shear–flexure interaction, pinching effect, strength and stiffness deterioration are clearly observed in numerous cyclic tests of RC coupling beams and shear walls. To develop an analytical model capable of accurately and efficiently assessing the expected seismic performance of RC coupled wall systems, it is critical to define the appropriate key components models (i.e., nonlinear models of RC wall piers/shear walls and coupling beams). Classic fiber beam element based on the theory of Euler–Bernoulli beam is frequently adopted to simulate the nonlinear responses of slender RC wall piers and coupling beams in the literature because it is able to accurately model the response characters from interaction of axial–bending moment at the section level. However, classic fiber beam element cannot capture the nonlinear behaviors of non-slender structures mainly controlled by nonlinear shear deformation. To overcome this shortcoming, a modified force-based fiber element (MFBFE) including shear effect is introduced and used as the analysis element of non-slender RC coupling beams and shear walls. At the section level, a novel shear model for RC coupling beams and an existed shear model for RC shear walls are respectively added to this fiber element to simulate nonlinear responses of these two key components. The analytical model for RC coupled walls hence is formed through integrating the proposed models of these two key components. The validations with different experimental results of cyclic tests including key compo-nents and structural system reported in the literature using these proposed models are performed. Good agreements are achieved for all of these proposed models via comparisons between predicted results and experimental data.

An IPD-based Incentive Mechanism to Eliminate Change Orders in Construction Projects in China

Jiankun Ma,Zhiliang Ma,Jiulin Li 대한토목학회 2017 KSCE Journal of Civil Engineering Vol.21 No.7

As in other countries where DBB (Design-Bid-Build) is used, one of the major problems in construction projects in China is cost overrun, and its main cause is change orders that occur during the construction phase. As a new mode of project delivery, IPD (Integrated Project Delivery) is considered capable of solving major problems including change orders in construction projects by involving contractors in the design phase to optimize design results and by introducing an incentive mechanism through which cost savings are shared among participants. However, the existing incentive mechanisms are difficult to adapt in China because contractors rely on change orders to obtain profit from construction projects. This research aims to establish an IPD-based incentive mechanism to eliminate change orders in construction projects in China. First, the final account statement of a completed construction project was analyzed to obtain the economic law of change orders. Second, based on this economic law, this research established an incentive mechanism composed of a compensation method for contractors, another compensation method for designers and a method for calculating their parameters. Finally, 21 completed construction projects and a new construction project were used to validate the incentive mechanism. This research provides not only an applicable IPD-based incentive mechanism to eliminate change orders in construction projects in China but also provides an approach for applying IPD in any other country where DBB is used and where the existing IPD incentive mechanisms cannot be directly applied.

Map-based cloning and functional analysis of the chromogen gene C in rice (Oryza sativa L.)

Shasha Zhao,Cuihong Wang,Jian Ma,Shuai Wang,Peng Tian,Jiulin Wang,Zhijun Cheng,Xin Zhang,Xiuping Guo,Cailin Lei 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

The chromogen gene C is critical for anthocyanin regulation in rice, and apiculus color is an important agronomic trait in selective breeding and variety purification. Mapbased cloning and in-depth functional analysis of the C gene will be useful for understanding the molecular mechanism of anthocyanin biosynthesis and for rice breeding. Japonica landrace Lijiangxintuanheigu (LTH) has red apiculi and purple stigmas. Genetic analysis showed that red apiculus and purple stigma in LTH co-segregated indicating control by a single dominant gene, or by two completely linked genes. Using 1,851 recessive individuals from two F2 populations, the target gene OsC was delimited to a 70.8 kb interval on chromosome 6 that contains the rice homologue of the maize anthocyanin regulatory gene C1. When the entire OsC gene and its full-length cDNA cloned from LTH were transformed into japonica cultivar Kitaake with colorless apiculi and stigmas all positive transformants had red apiculi but non-colored stigmas, validating that OsC alone was responsible for the apiculus color and represented the functional C gene. OsC was constitutively expressed in all tissues examined, with strongest expression in leaf blades. These results set a foundation to clarify the regulatory mechanisms of OsC in the anthocyanin biosynthetic pathway.

Transcriptomics Analysis Identified Candidate Genes Colocalized with Seed Dormancy QTLs in Rice (Oryza sativa L.)

Huaide Qin,Fuqing Wu,Kun Xie,Zhijun Cheng,Xiuping Guo,Xin Zhang,Jie Wang,Cailin Lei,Jiulin Wang,Long Mao,Ling Jiang,Jianmin Wan 한국식물학회 2010 Journal of Plant Biology Vol.54 No.5

Rice seed dormancy is an important trait related to the preharvest sprouting resistance of rice and is controlled by a polygene network. To identify the genes involved in this process, transcriptome analysis was applied to strong seed dormancy indica cultivar N22 and its weak dormancy mutant Q4646. The results showed that 280genes were significantly upregulated and 244 genes significantly downregulated in the seed of Q4646 as compared to N22 during 25 to 28 days after heading. These genes were mainly involved in stress response, Ccompound metabolism, plant development, DNA processing,and lipid metabolism. Some of these genes were colocalized with several reported dormancy QTLs, suggesting that they are possibly candidate genes underlying rice seed dormancy. Our work provides important clues for future effort to clone seed dormant genes in rice.