Analysis of Soil Nailing under Earthquake Loading in Malaysia Using Finite Element Method

2014 ◽  
Vol 695 ◽  
pp. 526-529 ◽  
Author(s):  
Mohd Faiz Mohammad Zaki ◽  
Wan Amiza Amneera Wan Ahmad ◽  
Afizah Ayob ◽  
Teoh Khai Ying

Soil nailing has become a widely accepted method and offers a practical solution towards construction of permanent retaining wall, slope stabilization and protection of existing cuts from failure. In Malaysia, soil nailing is typically performed on cut slope and installed with grouting as preventatives method due to erosion problem. However, although the effectiveness of soil nailing system may be well understood by practitioners, the slope failure and collapses of deep excavation are continuously occurs, especially for the construction in the earthquake zone. Malaysia has numerous experiences of earthquake even this country has been categorized as low seismicity group. Hence, it is become important in the scope of geotechnical engineering to analyze and study the effect of earthquake to soil nailing systems in Malaysia. Aims of this paper are to focus and study this technical issue using the application of finite element program. This research study selects PGA of 0.08g based on the location of major population in Malaysia. Safety factor was calculated in this finite element program using phi-c reduction. Soil nailing relatively give satisfactory response under seismic, so pseudo-static method is applied for seismic loading study. Based on the static analysis results, the FOS for the deep excavation stabilized with soil nailing is 1.54. However, by considering the earthquake or seismic loading, the FOS reduces to 1.16 and the percentage of reduction is about 25%. Total displacement was observed slightly difference in soil nailing analysis during an earthquake and static analysis

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.


2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Auchar Zardari ◽  
Hans Mattsson ◽  
Sven Knutsson ◽  
Muhammad Shehzad Khalid ◽  
Maria V. S. Ask ◽  
...  

Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.


1981 ◽  
Vol 17 (12) ◽  
pp. 1779-1789
Author(s):  
E. Haugeneder ◽  
W. Prochazka ◽  
P. Tavolato

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Aaron S Blom ◽  
Chun Xu ◽  
Liam P Ryan ◽  
Benjamin Jackson ◽  
Landi M Parish ◽  
...  

Objectives: High leaflet and chordal stresses contribute to recurrent mitral regurgitation after repair procedures. We hypothesized that a saddle-shaped annuloplasty ring would reduce leaflet stress compared to a similarly sized flat annuloplasty ring. To test this hypothesis we used a novel 3D echocardiographically-based finite element modeling (FEM) technique for quantifying regional mitral valve stress. Methods: Real-time 3D echocardiography was performed in 8 sheep before and after placement of either a 30mm flat annuloplasty (n=4) or a 30mm saddle-shaped annuloplasty. Full-volume data sets of the MV were obtained using an IE33 platform(Philips Medical Systems, Andover, Massachusetts) and exported to Cardio-View (Tomtec Imaging Systems, Munich, Germany) for image analysis. Individual leaflet data were then interpolated using Matlab (The Mathworks, Natick, Massachusetts). Triangulated leaflet surfaces were extracted and the data imported into a commercial finite element program (ABAQUS/Explicit 6.3, HKS Inc. Pawtucket, RI) to quantify regional stress distributions in all segments (P1, P2, P3 and A1, A2, A3) of the MV. Results: Peak anterior and posterior leaflet stresses after flat annuloplasty placement were 0.20±0.001MPa and 21±0.02MPa. Peak anterior and posterior leaflet stress after saddle-shaped annuloplasty placement was 0.19±0.02MPa and 13±0.01MPa (p<0.05 for the posterior leaflet stresses) Conclusions: Saddle-shaped annuloplasty design results in greater stress reduction in the posterior leaflet than standard flat annuloplasty rings and may, therefore, result in more durable repairs. This research has received full or partial funding support from the American Heart Association, AHA Great Rivers Affiliate (Delaware, Kentucky, Ohio, Pennsylvania & West Virginia).


Author(s):  
Parisa Hosseini Tehrani ◽  
Sajad Pirmohammad

There is a growing interest in the use of thin-wall structures as a means of absorbing the kinetic energy of a moving body. Multi-layered thin-wall structures are more efficient and lighter than thick-wall structures, and show better crashworthiness characteristics. In this task, several concentric aluminum thin wall tubes as energy absorber under axial and oblique loading are studied and optimum combination of these tubes is presented. The weight of the tubes is optimized while crashworthiness of tubes is not compromised. The commercial finite element program LS-DYNA that offers non-linear dynamic simulation capabilities was used in this study.


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