Numerical analysis of effective parameters in direct shear test by hybrid discrete – finite element method

Q: How can I download an article?

To download an article from SID, first log in to the site, search for the article title, and click on the 'Download Article' option.

Q: How can I download an ISI article?

To download an ISI article on SID, enter the keyword or article title in the search bar, view the relevant results, click on the desired article, and select the 'Download Article' option.

Q: How can I access the SID database?

To access the SID database, visit SID.ir, create an account, and log in to access scientific resources.

Q: Is downloading articles from SID free?

Some articles on SID are available for free, while others require payment. Details are specified on the article's page.

Afrazi m.; YAZDANI M.; FAKHIMI A.A.; Alitalesh M.

Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Journal Paper

Paper Information

Journal: Modares Civil Engineering journal Year:2018 | Volume:18 | Issue:3 Page(s): 13-24

Download Full-Text

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Persian Verion

View:

783

Download:

Cites:

Information Journal Paper

Title

Numerical analysis of effective parameters in direct shear test by hybrid discrete – finite element method

Author(s)

Afrazi m. | YAZDANI M. | FAKHIMI A.A. | Alitalesh M. | Issue Writer Certificate

Keywords

Direct Shear TestQ1

Numerical ModelingQ2

Finite Element MethodQ2

Discrete Element MethodQ2

Experimental testsQ2

Abstract

Determination of soil engineering properties such as shear strength is essential to analysis many geotechnical problems. Therefore, determination of the reliable values for this parameter is very important. For this purpose, Direct Shear Test as one of the oldest test to examine the shear strength of soils, is conducted on soil samples. There are too many factors which could affect results of Direct Shear Test. Laboratory tests are expensive, difficult and time consuming, hence using numerical method to simulate experimental test and study effective factors can be useful. In this paper Direct Shear Test was numerically modeled using CA2 hybrid finite element-Discrete Element Method code. CA2 solves explicitly equations of motion together with macro or micro-constitutive equations. In this study, shear box is modeled using finite element grids and a discrete element model is implemented for simulation of soil specimen within the box. Appropriate boundary conditions are assigned to the box, normal stress is applied to the specimen using finite element grid and shear velocity was finally applied to the model. Shear force is applied to the model by a constant velocity 4. 5×10-9 meter/cycle. It should be noted that, shear velocity is applied to the upper part of shear box, and applied velocity is considered small enough to confirm that there is a quasi-static condition in numerical solution. In this study using numerical simulation, the effects of box dimension, genesis pressure, normal stress, shear velocity and box wall friction on shear strength of the soil specimen are investigated. Study of box dimension effect, shows that peak effective internal friction angle in small direct shear box and large direct shear box differs about 6° , and cohesion decreases by increasing box dimension but for box dimensions bigger than 20cm, changes in box dimension has no significant effect on resulted soil cohesions. Investigation of influence of genesis pressure shows that, incrementing genesis pressure, cohesion increases too, that can be attributed to the SOCPI model provided in CA2. In SOCPI model by increasing genesis pressure the overlap between cylinders increases. In SOCPI model by increasing overlap the cohesion increases but peak friction angle doesn’ t change too much. Normal stress analysis shows that, increasing normal stress will increase the interlocking between soil particle and this tends to increas cohesion of the soil model. Shear velocity is another parameter which is studied in this research. Results show that by increasing shear velocity, soil shear strength increases. It should be mentioned that shear velocity should be considered as small enough to provide a quasi-static condition. In this research, friction of shear box wall was also investigated. When there is friction between box wall and soil particles, shear strength can be underestimated for contractant soils or overestimated for dilatant soils. In this paper, it is shown that if soil has no significant volume changes, peak shear strength is not affected by friction between soil particle and box wall.

Cites

No record.

References

No record.

Cite

APA: Copy

Afrazi, m., YAZDANI, M., FAKHIMI, A.A., & Alitalesh, M.. (2018). Numerical analysis of effective parameters in direct shear test by hybrid discrete – finite element method. MODARES CIVIL ENGINEERING JOURNAL, 18(3 ), 13-24. SID. https://sid.ir/paper/256900/en

Vancouver: Copy

Afrazi m., YAZDANI M., FAKHIMI A.A., Alitalesh M.. Numerical analysis of effective parameters in direct shear test by hybrid discrete – finite element method. MODARES CIVIL ENGINEERING JOURNAL[Internet]. 2018;18(3 ):13-24. Available from: https://sid.ir/paper/256900/en

IEEE: Copy

m. Afrazi, M. YAZDANI, A.A. FAKHIMI, and M. Alitalesh, “Numerical analysis of effective parameters in direct shear test by hybrid discrete – finite element method,” MODARES CIVIL ENGINEERING JOURNAL, vol. 18, no. 3 , pp. 13–24, 2018, [Online]. Available: https://sid.ir/paper/256900/en

Related Journal Papers