scholarly journals Elastoplastic analysis of normal stiffness of bore wall of the rock-socketed pile based on Hoek-Brown failure criterion and cavity expansion theory

2020 ◽  
Vol 8 (7) ◽  
pp. 239-244
Author(s):  
Jiang Xu ◽  
Guoliang Dai ◽  
Weiming Gong
Author(s):  
Meen-Wah Gui ◽  
Dong-Sheng Jeng

The application of cavity expansion theory in the back estimation of cone penetration tests conducted in calibration chambers has been carried out by many researchers. However, the theory is seldom employed by centrifuge modelers. Based on the work of spherical cavity expansion of previous researchers, this study proposed an analytical solution that incorporates the effects of cone geometry and surface roughness and the effect of compressibility to estimate the cone tip resistance. The calculated results are compared with the measured cone penetration resistance of four cone penetration tests performed in the centrifuge. The cone penetration tests were conducted in granular soil specimens having relative densities ranging between 54% and 89%. The comparison demonstrates the capacity of the cavity expansion theory in the prediction of the centrifuge cone penetration resistance.


Author(s):  
N Khazraiyan ◽  
GH Liaghat ◽  
H Khodarahmi ◽  
N Dashtian-Gerami

In this article, a semi-analytical model has been developed for perforation of a hard projectile into a single- and two-layer concrete targets. The model is based on the dynamic cavity expansion theory and the reflection of compressive waves from the end of the concrete targets. The effect of friction coefficient is also investigated in the analysis. Numerical modeling of the problem has been performed in LS-DYNA code. Holmquist–Johnson–Cook, plastic kinematic, and rigid material models have been employed for the concrete, the backing plate, and the projectile, respectively. The impact velocity range, considered in this study, is between 300 and 800 m/s. No projectile erosion is considered in this velocity range. The analytical results of the investigation for both single- and two-layer concrete targets are in a good agreement with numerical simulations and experimental data.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Suman Manandhar ◽  
Noriyuki Yasufuku

On the basis of evidence from model tests on increasing the end-bearing behavior of tapered piles at the load-settlement curve, this paper proposes an analytical spherical cavity expansion theory to evaluate the end-bearing capacity. The angle of tapering is inserted in the proposed model to evaluate the end-bearing capacity. The test results of the proposed model in different types of sands and different relative densities show good effects compared to conventional straight piles. The end-bearing capacity increases with increases in the tapering angle. The paper then propounds a model for prototypes and real-type pile tests which predicts and validates to evaluate the end-bearing capacity.


2010 ◽  
Vol 44-47 ◽  
pp. 3060-3066 ◽  
Author(s):  
Yong Gang Bao ◽  
Nian Mei Zhang ◽  
Gui Tong Yang

This paper presents a theoretical approach for investigating the perforation of aluminum alloy foam target against rigid ogive-nosed projectile. The target is composited by two different density single-layer aluminum alloy foam boards. The dynamic cavity expansion theory is applied to formulate analytical model. The perforating process can be divided into 8 stages. The effects of shank diameter, shank length and caliber-radius-head (CRH) on perforating resistance force and kinetic energy variation are analyzed. The results demonstrate that velocity limit increases significantly with the raising of shank diameter in the case of fixed mass and CRH has no significant influence on residual velocity and velocity limit. And the residual velocity can be predicted by the known striking velocity and velocity limit.


Author(s):  
Hai-Jun Wu

Abstract The penetration depth of rigid projectiles is investigated using the modified spherical cavity expansion theory and the Holmquist–Johnson–Cook (HJC) model for the concrete targets, in which the model parameters used in the Mohr–Coulomb Tresca-limit yield criterion are obtained by the triaxial compression tests. By comparing the cavity expansion pressures of the concrete samples with two different types of aggregate, the influence of the aggregate hardness on the penetration processes is discussed. With the analysis of the tractions acted on the projectile nose, the influences of the projectile and target material properties as well as the projectile structure on the transition impact velocity are also discussed. By comparing the theoretical results with the experimental data, two penetration mechanisms are demonstrated for the ogive-nose projectile penetration into concrete with the striking velocities up to 2.0 km/s.


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