Development of Dynamic Simple Shear Apparatus for Small Strain Dynamic Tests on Unsaturated Granular Soils by Bender Element and Ultrasonic Sensors

Document Type : Original Article

Authors

1 M.Sc. of Geotechnical Engineering, Depaertment of Civil Engineering, Sharif University of Technology, Tehran, Iran.

2 Associate Profesor, Department of Civil Engineering, Depaertment of Civil Engineering, Sharif University of Technology, Tehran, Iran.

3 Ph.D. of Geotechnical Engineering, Department of Civil Engineering, Sharif University of Technology, Tehran, Iran.

Abstract

Shear modulus and confined modulus are important parameters for static and dynamic analysis in geotechnical applications. Cyclic simple shear apparatus had been developed by mounting bender element and ultrasonic sensors to measure continuous shear wave and pressure wave velocities for determination of Gmax and M. For this purpose two new pedestals have been fabricated on which HAE ceramic disc and sensors were mounted. A pressure control panel and a hanging column system have been designed to apply high and low matric suction values with high accuracy. Finally, some tests was conducted to verify the result of device performance and to compare with the theoretical results of unsaturated soils.  

Keywords


1. Viggiani, G., Atkinson, H., (1995). Interpretation of bender element tests, International Journal of Rock Mechanics and mining science,  8(32), 373A.
2. Bennell, J. D., Taylor Smith, D., Davis, A. M., (1984). Resonant column testing of marine sediments, Proc. Oceanogr. International Bright., 1.
3. Brignoli, K. H., Gotii, E. G. M., Stokoe, M., (1996). Meashearment of Shear Waves in Laboratory Specimens by Means of Piezoelectric Transducers, Geotechnical testin journal, 19(4), 384-397.
4. Dyvik, R., Madshus, C., (1985). Lab Measurements of G m a x Using Bender Elements, in Advances in the art of testing soils under cyclic conditions, 186-196.
5. Kim, N. R., Kim, D. S., (2010). A shear wave velocity tomography system for geotechnical centrifuge testing, Geotechnical testing journal, 33(6), 121-132.
6. Eseller-Bayat, E., Gokyer, S., Yegian, M. K., Deniz, R. O., Alshawabkeh, A., (2013).   Bender elements and bending disks for measurement of shear and compression wave velocities in large fully and partially saturated sand specimens, North eastern university.
7. Kjellman, W., (1951). Testing the shear strength of clay in Sweden, Geotechnique, 2(3), 225-232.
8. Bjerrum, L., Landva, A., (1966). Direct simple-shear tests on a Norwegian quick clay, Geotechnique, 16(1). 1-20.
9. Ishihara, K., Yamazaki, F., (1980). cyclic simple shear tests on saturated sand in multi-directional loading, Japanese geotechnical society, 20(1), 45-59.
10. Boulanger, R. W., Seed, R. B., (1995). Liquefaction Of Sand under Bidirectional Monotonic and Cyclic Loading, Journal of Geotechnical Engineering, 121(12), 870-878.
11. Jafarzadeh, F., Ahmadinezhad, A., Sadeghi, H., (2014). Coupled effects of suction and degree of saturation on large strain shear modulus of unsaturated sands, no. Kammerer 2002, 1559–1564.
12. Astm D5521–05, (2006). Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System), ASTM Stand. Guid.,1–5.
13. ASTM 854-02, (2002). Standard Test Methods for Specific Gravity of Soil Solids by Water Pycnometer 1, ASTM Stand. Guid., 1–8.
14. ASTM D422-63, (2007). Standard Test Method for Particle-Size Analysis of Soils,” ASTM Stand. Test Method, D422–63 (R, no. Reapproved 2007, pp. 1–8.
15. ASTM D4253-00, (1984). Standard Test Methods for Minimum Index Density and Unit Weight of Soils and Calculation of Relative Density 1, ASTM Stand. Test Method, I, 158–165.
16. ASTM D4253-00, (2013). Standard Test Methods for Maximum Index Density and Unit Weight of Soils Using a Vibratory Table, ASTM Stand., 00, no. Reapproved 2006, 1–15.
17. Li, X., Zhang, L. M., Li, J. H., (2009). Development of a modified axis translation technique for measuring SWCCs for gravel soils at very low suctions, Geotechnical testing journal,32(6), 1-11.