scholarly journals Research on the RC Panel Experiments with Cushion Layer Upon Rockfall Impact

2019 ◽  
Vol 7 (3) ◽  
pp. 56
Author(s):  
Mei Xuefeng ◽  
Hu Xiewen ◽  
Wu Jianli
Keyword(s):  
Cushion Layer

Simulation Analysis for Reinforced Concrete Aqueduct of Lijia Pumping Station

2014 ◽  
Vol 488-489 ◽  
pp. 605-608
Author(s):  
Xiang Zan Xie
Keyword(s):  
Reinforced Concrete ◽  
Simulation Analysis ◽  
Water Pressure ◽  
Water Diversion ◽  
Distribution Law ◽  
Masonry Arch ◽  
Pumping Station ◽  
Earthquake Effect ◽  
Concrete Masonry ◽  
Cushion Layer

Reinforced concrete masonry arch aqueduct is a common water diversion engineering structure. Aqueduct is decorated on the concrete cushion layer, cushion layer effects on masonry arch, the structures stress is uniform, carrying capacity is strong. This paper adopts finite element method to carry out force analysis for reinforced concrete masonry arch aqueduct of Lijia pumping station, considering aqueduct weight, water pressure and earthquake effect, etc. Researching stress and deformation distribution law of reinforced concrete masonry arch aqueduct.

Specimen Molding Method of Chip Seal in Laboratory

2011 ◽  
Vol 374-377 ◽  
pp. 1904-1907
Author(s):  
Yu Hua Li ◽  
Hai Xiang Li ◽  
Yu Xing Liu ◽  
Jing Yun Chen
Keyword(s):  
Asphalt Concrete ◽  
Visual Inspection ◽  
Performance Test ◽  
Construction Process ◽  
Molding Method ◽  
Chip Seal ◽  
Sand Patch ◽  
Emulsified Asphalt ◽  
Cushion Layer

Chip seal is most frequently used as preventive maintenance (PM) treatments on asphalt pavement. However, it’s difficult to make the performance test of chip seal in laboratory. In this paper, the specimen molding method of chip seal is established in laboratory. Firstly, considering the structure and technique condition of the original pavement, a cushion layer of asphalt concrete (AC) is used as under layer of the specimen. Secondly, the construction process of chip seal is simulated in laboratory, which includes spraying emulsified asphalt and/or glass fiber, spreading aggregate, initial rolling and conservation, post-stage rolling and conservation in interval for some time. Lastly, visual inspection and sand patch test are used to evaluate the quality of the specimen. Research results show that the method of specimen molding and test in laboratory could relatively accurately simulate, evaluate and forecast the performance of the chip seal.

Analytical Model for Rockfall Protection Galleries - a Blind Prediction of Test Results and Conclusion

2011 ◽  
Vol 82 ◽  
pp. 722-727 ◽  
Author(s):  
Kristian Schellenberg ◽  
Norimitsu Kishi ◽  
Hisashi Kon-No
Keyword(s):  
Degrees Of Freedom ◽  
Large Scale ◽  
Test Results ◽  
Blind Prediction ◽  
Proposed Model ◽  
Input Parameters ◽  
Scale Test ◽  
Definition Of ◽  
Protective Structures ◽  
Cushion Layer

A system of multiple degrees of freedom composed out of three masses and three springs has been presented in 2008 for analyzing rockfall impacts on protective structures covered by a cushion layer. The model has then been used for a blind prediction of a large-scale test carried out in Sapporo, Japan, in November 2009. The test results showed substantial deviations from the blind predictions, which led to a deeper evaluation of the model input parameters showing a significant influence of the modeling properties for the cushion layer on the overall results. The cushion properties include also assumptions for the loading geometry and the definition of the parameters can be challenging. This paper introduces the test setup and the selected parameters in the proposed model for the blind prediction. After comparison with the test results, adjustments in the input parameters in order to match the test results have been evaluated. Conclusions for the application of the model as well as for further model improvements are drawn.

scholarly journals A Study on Dynamic Amplification Factor and Structure Parameter of Bridge Deck Pavement Based on Bridge Deck Pavement Roughness

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Fei Han ◽  
Dan-hui Dan ◽  
Hu Wang
Keyword(s):  
Bridge Deck ◽  
Amplification Factor ◽  
Amplification Coefficient ◽  
Dynamic Amplification Factor ◽  
Vibration Load ◽  
Pavement Roughness ◽  
Composite Bridge ◽  
Dynamic Amplification ◽  
Cushion Layer ◽  
Bridge Deck Pavement

In order to study the coupled influence of deck pavement roughness and velocity on dynamic amplification factor, a 2-DOF 1/4 vehicle model is employed to establish the vehicle-bridge-coupled vibration system. The random dynamic load of running vehicle simulated by software MATLAB is applied on bridge deck pavement (BDP) through ANSYS software. Besides, the influence of BDP parameters on control stress under static load and random vibration load is analyzed. The results show that if the surface of BDP is smooth, the dynamic magnification coefficient would first increase and then decrease with increasing of vehicle velocity and reach its maximum value when v = 20 m/s; if the surface of BDP is rough, the maximal and minimum values of the dynamic amplification coefficient (DAC) occur, respectively, when the velocity reaches 10 m/s and 15 m/s. For a composite bridge deck with the cushion layer, the thickness of asphalt pavement should be not too thick or thin and better to be controlled for about 10 cm; with the increasing of cushion layer thickness, the control stress of deck pavement is all decreased and show similar change regularity under effect of different loads. In view of self-weight of structure, the thickness of the cushion layer is recommended to be controlled for about 4 cm.

On Stability Improvement of Gravity Type Onshore and Offshore Structures

2005 ◽  
Author(s):  
Hemanta Hazarika
Keyword(s):  
Finite Thickness ◽  
Interaction Model ◽  
Offshore Structures ◽  
Seismic Stability ◽  
Seismic Load ◽  
Earthquake Loading ◽  
Earthquake Motion ◽  
Constitutive Properties ◽  
Cushion Layer ◽  
Surrounding Soil

A protective cushion layer sandwiched between a gravity type caisson and the surrounding soil can improve the seismic stability of the caisson. In this paper, an interaction model was developed for analyzing such structure under earthquake loading. Interfaces on either side of the cushion were modeled as elements of finite thickness having different stiffness and constitutive properties. Participation from each element of the interaction system was taken into the account by incorporating appropriate factors at the respective interfaces. Seismic analyses were performed on a gravity-type caisson subjected to an actual earthquake motion. Comparison of the analysis results with a similar caisson without any protective cushion showed that the use of cushion yields a significant reduction of seismic load on the structure.

3D Finite Element Analysis on ChaHanWuSu CFRD Built on Thick Alluvium Deposits

2011 ◽  
Vol 243-249 ◽  
pp. 4482-4487 ◽  
Author(s):  
Da Wei Sun ◽  
Kang Ping Wang ◽  
Hui Qin Yao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Computer Calculation ◽  
Element Analysis ◽  
Produce Water ◽  
3D Finite Element ◽  
3D Mesh ◽  
3D Finite Element Analysis ◽  
The Face ◽  
Cushion Layer

As a very popular dam style, more concrete- faced rockfill dams have been built in the world, but there is presently only a few high CFRDs with dam height more than 100m built on thick alluvium deposits. ChaHaWuSu CFRD with dam height 107.60m and the maximum thickness of alluvium deposits 46.70m, has been built in Xinjiang province, China recently. The excessive of displacement of foundation and dam body may lead to big deformation of peripheral joint and cause the failure of seal materials and produce water leakage. Therefore, 3D finite element analysis was carried out to estimate the deformation of dam. Firstly, 3D mesh including surrounding mountain and alluvium deposits was established by use of advanced grid discreteness technique. Secondly, Desai thin layer elements were adopted to model the interface between the face slab and cushion layer. Moreover, joint elements were adopted to model the joints between the face slab and plinth, plinth and connecting slab, connecting slab and connecting slab, connecting slab and diaphragm wall. Finally, large scales of equations solving method were adopted in the procedure thus the computer calculation time was greatly reduced. The calculation result was compared with the monitored deformation date of ChaHaWuSu CFRD. All in all, the above research will do much benefit to the CFRD design on thick alluvium deposits.

Study on Friction Coefficient of Spiral Case with Cushion Layer in Large-Scale Hydropower Plant

2011 ◽  
Vol 71-78 ◽  
pp. 4248-4251
Author(s):  
Jian Wei Zhang ◽  
Yi Na Zhang ◽  
Shu Fang Yuan
Keyword(s):  
Coefficient Of Friction ◽  
Large Scale ◽  
Water Pressure ◽  
Structural Type ◽  
Hydropower Plant ◽  
Finite Element Program ◽  
Spiral Case ◽  
Element Program ◽  
Cushion Layer ◽  
Elastic Cushion

Elastic cushion layer between the steel spiral case and surrounding concrete is often used as a structural type in large-scale hydropower plant in China. In view of the uncertainty of the optimal elastic coefficient of friction and the transfer mechanism of internal water pressure to the surrounding concrete, Spiral case with cushion layer of large-scale hydropower plant is simulated with ANSYS nonlinear finite element program, considering the slip contact characteristics between steel spiral case and the surrounding concrete, the more reasonable coefficient of friction between the steel spiral case and concrete is studied. This provides reliable theoretical analysis for the design of large-scale hydropower plants.

Modeling of low-cement extruded curb of concrete-faced rockfill dam

2011 ◽  
Vol 48 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Ga Zhang ◽  
Jian-Min Zhang
Keyword(s):  
Numerical Simulation ◽  
Damage Model ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Direct Simulation ◽  
Construction Technique ◽  
Displacement Analysis ◽  
Rockfill Dam ◽  
The Face ◽  
Cushion Layer

As the key structure of a practical construction technique, the low-cement extruded curb has been widely used in recent concrete-faced rockfill dams (CFRDs). The extruded curb exhibits significant interactions with the neighboring gravels and with the face slab. These interactions were investigated using element tests, and a new model was proposed. This model is composed of three parts: (i) the equivalent slab that is described using an ideal elastoplasticity model, (ii) the equivalent interface between the curb and the gravel cushion layer that is described using an elastoplasticity damage model, and (iii) the interface between the curb and the face slab that is described using a modified ideal elastoplasticity model. This model was verified via a two-dimensional numerical simulation of an ideal CFRD to capture the main behavior of the extruded curb with interactions between the extruded curb and the neighboring soil – face slab, employing a significantly smaller number of elements and a shorter calculation than direct simulation. The model was used to perform a three-dimensional stress–displacement analysis of the Bakun CFRD (205 m in height), and the results showed that the extruded curb causes a change in the stress of the face slab.

Experimental Research on the Stiffness of Gravel Cushion with the Influence of Geogrid

2014 ◽  
Vol 529 ◽  
pp. 242-246
Author(s):  
Li Sheng Huang ◽  
Jie He
Keyword(s):  
Experimental Research ◽  
Optimization Design ◽  
Static Load ◽  
Load Test ◽  
Experimental Results ◽  
Static Load Test ◽  
Modulus Of Deformation ◽  
Fixed Condition ◽  
Cushion Layer ◽  
Different Thickness

To study the influence law of Geogrid’s effects on the stiffness of grave cushion, cushions of nine different kinds are designed and are carried out static load test of model respectively. The effects of different thickness of cushion layer , different geogrid layers and different laying position of gravel cushion layer on gravel cushion and reinforced grave cushion modulus of deformation are analyzed through the experimental results. Results show that ,under other fixed condition ,modulus of deformation of grave cushion is bigger than that of pure grave cushion layer, and the modulus of deformation of thinner layer of grave cushion is increased much higher; modulus of deformation of the gravel cushion layer of geogrid is increased along with the thinner layer, added gravel cushion layers of geogrid and the move up of the position; the effects of the location of geogrids on cushion modulus of deformation decreases with the increase of the grating layer. Research results provide a referential basis for the optimization design for reinforcement pads in composite foundations.

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