Cyclic Load Test and Shear Strength Degradation Model for Columns with Limited Ductility Tie Details

2019 ◽  
Vol 145 (2) ◽  
pp. 04018249 ◽  
Author(s):  
Chul-Goo Kim ◽  
Hong-Gun Park ◽  
Tae-Sung Eom
2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Bo Tao ◽  
Guanghua Wu ◽  
Zhouping Yin ◽  
Youlun Xiong

Hygrothermal environments can degrade anisotropic conductive adhesive (ACA) joints by weakening the shear strength of adhesive interface. In this paper, the shear strength degradation model of ACA joints under hygrothermal conditions was formulated through experimental testing and theoretical modeling. The shear strength degradation data were obtained from different hygrothermal aging tests and the ACA moisture properties were characterized for the corresponding hygrothermal conditions. Theoretical models considering the hygrothermal factors of T (temperature), RH (relative humidity), and t (time), were used to fit the shear strength degradation data. It was found that the inverse exponential law was the best candidate model to predict the degradation data. The shear strength degradation model of ACA joints under hygrothermal conditions was proposed, where the relationship of the S (shear strength) and the hygrothermal factors (T, RH, and t) was expressed in an analytical model. The degradation model was validated by experiments, and the model predictions agreed well with the test results.


2020 ◽  
Vol 57 (8) ◽  
pp. 1183-1196 ◽  
Author(s):  
Ting-kai Nian ◽  
Yan-jun Zhang ◽  
Hao Wu ◽  
Guang-qi Chen ◽  
Lu Zheng

The reliable numerical simulation of the landslide process contributes to the establishment of evidence-based disaster mitigation measures in seismically active zones. To achieve this goal, a simple and unified state-dependent shear strength model of discontinuities is presented to describe the shear strength degradation in a seismic landslide process. The proposed model establishes a relationship between the shear strength parameters and the global safety factor of the slope by assuming that the slope instability (or landslide initiation) is accompanied by an instantaneous shear strength degradation of discontinuities. To realize the model numerically, the algorithms for the computation of global safety factor and the modification of shear strength parameters were incorporated into the discontinuous deformation analysis (DDA). Subsequently, the kinematic accuracy of the improved DDA method was validated by comparisons with theoretical solutions for the dynamic sliding of a block on an inclined plane. Numerical simulations of the Daguangbao landslide triggered by the Wenchuan earthquake were performed using the improved DDA method. The results illustrate that the shear strength degradation of discontinuities affect the evolution process, travel distance, and post-failure shape of the seismic landslide significantly.


Géotechnique ◽  
2014 ◽  
Vol 64 (6) ◽  
pp. 493-501 ◽  
Author(s):  
J.A. PINEDA ◽  
E. ROMERO ◽  
M. DE GRACIA ◽  
D. SHENG

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