Numerical Simulation for Dynamic Response of EPS Geofoam Seismic Buffers

2011 ◽  
Vol 378-379 ◽  
pp. 256-261
Author(s):  
Yi Min Wang ◽  
Huan Li ◽  
Hui Zhang

Numerical simulation for dynamic response of EPS geofoam seismic buffers placed behind the rigid retaining walls was carried out with the Fast Lagrangian Analysis for Continuum method (FLAC) .The considerations of setting boundary condition of the numerical model, inputting and correcting the dynamic time series of seismic acceleration, and selecting the proper damping were discussed. The coincidence relations of compression-time for EPS geofoam buffers and the horizontal soil pressure -time for retaining wall were numerically calculated by using the proposed model. The calculating results were compared with the physical testing results. The comparisons showed that there were good agreements between the numerical data and the measured data. The numerical results indicate that EPS panels placed between the rigid retaining wall and the backfill soil have a good effect on reducing horizontal earth force during shaking acceleration and can act as seismic buffers against earthquake. The FLAC model provides a feasible way to analyze the dynamic response of EPS geofoam seismic buffers for further researches.

2014 ◽  
Vol 672-674 ◽  
pp. 1863-1867
Author(s):  
Jian Qing Wu ◽  
Ying Yong Li ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Qing Yu Meng ◽  
...  

In order to study anchor relaxation of pressure dispersive retaining wall, the numerical simulation model was designed to simulate the retaining wall with single anchor plate. The results showed that the pressure dispersive retaining wall had good overall stability. Anchor Relaxtion had two sudden changes. As a result, the lateral soil pressure near the anchor had been released and the displacement Significantly increased.


2013 ◽  
Vol 353-356 ◽  
pp. 312-317
Author(s):  
Ying Yong Li ◽  
Li Zhi Zheng ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Zhi Chao Xue

In order to ensure the security of gravity retaining wall in the high fill subgrade, the design of gravity retaining wall with anchors is proposed,the characteristic of the new wall is that comment anchors are added to the traditional gravity retaining wall,by friction anchors provide lateral pull to the wall so the stability of the new wall is improved. Because of the constraints of anchors, the lateral free deformation is influenced and the soil pressure distribution is very complicated, field tests showed that soil pressure distribution is nonlinear and pressure concentrate in anchoring position. In order to reveal the supporting mechanism of retaining wall and propose the soil pressure formula, the model test of anchor retaining wall is made and numerical simulation is done. The results show that soil pressure appears incresent above the anchor and decreasing below the anchor, the soil pressre also grew larger away from the anchor proximal in the horizontal direction.


2013 ◽  
Vol 477-478 ◽  
pp. 562-566
Author(s):  
Fang Ding He ◽  
Guang Jun Guo ◽  
Zhi Dong Zhou ◽  
Jian Qing Wu

The anchor plays a very important role in gravity retaining wall. The displacement of retaining and soil pressure distribution with anchor is different from that without anchor. The numerical simulation software FLAC3D is used to analysis the soil pressure distribution characteristics of gravity retaining wall. The results show that the anchor plays a supporting role in gravity retaining wall. There is a critical length in the anchor in gravity retaining wall. The soil pressure distribution of gravity retaining wall with anchor does not conform to the classical Coulomb linear distribution theory and more research is needed for the soil pressure distribution theory. The research has important guiding significance on the design and construction development of gravity retaining wall.


2013 ◽  
Vol 353-356 ◽  
pp. 927-932
Author(s):  
Ji Cheng Wang ◽  
Ai Liu ◽  
Chuan Fa Yan

Numerical simulation was used to study the relationship between reinforced earth retaining wall gradient and geogrid strain. Research results show that when the load on the wall top is small, the function of geogrids in the upper section of retaining wall is not brought to full play, the angle between potential rupture surface and horizontal plane is small and resembles Rankines active soil pressure rupture surface, and it is far from wall face. When the load on wall top increases, potential rupture surface becomes steep, the distance between the surface and wall face is about one third of wall height. Inclined wall face also displays this property. The gentler the reinforced earth retaining wall gradient is, the smaller the geogrid stress is, and the safer the wall is. However, when gradient drops below 1:0.4, safety increase becomes vague. When wall gradient is 1:0.3, geogrid stress is most uniformly distributed, and thus has the highest use efficiency and the wall is the most cost-effective.


Author(s):  
Ripon Hore ◽  
Sudipta Chakraborty ◽  
Ayaz Mahmud Shuvon ◽  
Md. Fayjul Bari ◽  
Mehedi A. Ansary

2011 ◽  
Vol 328-330 ◽  
pp. 1755-1758
Author(s):  
Han Xiao Liu ◽  
Zhong Liu ◽  
Huai Liang Li ◽  
Xin Xin Feng ◽  
Zhen Zhong Xing

In this paper, the continuity equation, momentum equation and the k-ε turbulence equation were introduced to simulate the flow field of the multiple vortex bodies in different spacing cases. Found that each vortex body had good effect in producing vortex, and the greater flow field spacing, the smaller the highest velocity; the turbulence intensity is increasing gradually from the former vortex body to the next one, and there may be a best spacing between the vortex bodies which makes the best turbulent intensity. All of these theories provide a train of thought for the turbulent coalescence mechanism.


2014 ◽  
Vol 529 ◽  
pp. 102-107
Author(s):  
Hai Bo Luo ◽  
Ying Yan ◽  
Xiang Ji Meng ◽  
Tao Tao Zhang ◽  
Zu Dian Liang

A 7.8m/s vertical drop simulate of a full composite fuselage section was conducted with energy-absorbing floor to evaluate the crashworthiness features of the fuselage section and to predict its dynamic response to dummies in future. The 1.52m diameter fuselage section consists of a high strength upper fuselage frame, one stiff structural floor and an energy-absorbing subfloor constructed of Rohacell foam blocks. The experimental data from literature [6] were analyzed and correlated with predictions from an impact simulation developed using the nonlinear explicit transient dynamic computer code MSC.Dytran. The simulated average acceleration did not exceed 13g, by contrast with experimental results, whose relative error is less than 11%. The numerical simulation results agree with experiments well.


2013 ◽  
Vol 765-767 ◽  
pp. 3158-3161
Author(s):  
Jun Liu ◽  
Zheng Li Zhang

Tests of bird strike have been carried out on plate made from LY-12 Aluminium. The test was down with the projectile impacting the target perpendicularly at velocity of 40m/s, 80m/s, 120m/s respectively. The displacement-time history curves and strain-time history curves of on LY-12 Aluminium plate were measured. The good agreement of the results between two specimens in one group indicated that the results tested in the presnet paper are reliable. The dynamic response of the plate and damage modes of the bird influenced by striking velocity were analyzed. The peak value of the displacement linear enlarged with the increasing of the striking velocity. The test results in the present paper provided valuable data for aircraft design impacted by bird, and also provided abundant test datas for the numerical simulation model applied in bird striking.


Author(s):  
Tomoaki Utsunomiya ◽  
Shigeo Yoshida ◽  
Soichiro Kiyoki ◽  
Iku Sato ◽  
Shigesuke Ishida

In this paper, dynamic response of a Floating Offshore Wind Turbine (FOWT) with spar-type floating foundation at power generation is presented. The FOWT mounts a 100kW wind turbine of down-wind type, with the rotor’s diameter of 22m and a hub-height of 23.3m. The floating foundation consists of PC-steel hybrid spar. The upper part is made of steel whereas the lower part made of prestressed concrete segments. The FOWT was installed at the site about 1km offshore from Kabashima Island, Goto city, Nagasaki prefecture on June 11th, 2012. Since then, the field measurement had been made until its removal in June 2013. In this paper, the dynamic behavior during the power generation is presented, where the comparison with the numerical simulation by aero-hydro-servo-mooring dynamics coupled program is made.


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