Penetration Resistance Of Sands Research Articles

Calibration Chamber Size Effects on Penetration Resistance in Sand

Calibration Chamber Size Effects on Penetration Resistance in Sand

Closure to “Calibration Chamber Size Effects on Penetration Resistance in Sand” by R. Salgado, J. K. Mitchell, and M. Jamiolkowski

Closure to “Calibration Chamber Size Effects on Penetration Resistance in Sand” by R. Salgado, J. K. Mitchell, and M. Jamiolkowski

Calibration Chamber Size Effects on Penetration Resistance in Sand

Calibration chamber tests provide an effective way to study cone penetration resistance in sands under controlled conditions. Calibration chamber tests are performed in large soil samples with known densities, consolidated to desired stresses, and subjected to known boundary conditions. Results from calibration chamber tests can be used to establish the relationship between cone resistance, soil density, and stress state. However, the penetration resistance measured in a calibration chamber differs from that measured in the free field because of chamber size and boundary condition effects. There has been considerable uncertainty about these effects, precluding use of the results of calibration chamber research with greater confidence. In this paper, a penetration resistance theory recently developed is used to quantify chamber size effect, to investigate the factors it depends on, and to show how to correct calibration chamber test penetration resistance values to free-field conditions. The theoretical results are compared with available experimental results.

Cavity Expansion and Penetration Resistance in Sand

A theory, based on cavity expansion and stress rotation analyses, is developed for computing the cone penetration resistance of sand. The sand is modeled as a nonlinear elastic-plastic material. The theory can be used for analysis of calibration chamber tests, as it takes full account of chamber size and boundary conditions. The theory was used to calculate values of cone penetration resistance for the conditions corresponding to each of about 400 cone penetration tests performed in different calibration chambers. The chamber diameters range from 0.76 to 1.20 m and the cone penetrometer diameters from 1 to 3.57 cm. The samples were prepared of different sands at different densities and stresses. The agreement between theoretical and experimental values was better than ±30% in most cases.

Effect of aging on the penetration resistance of sands: Reply

Effect of aging on the penetration resistance of sands: Reply

Effect of aging on the penetration resistance of sands: Discussion

Effect of aging on the penetration resistance of sands: Discussion

Effect of aging on the penetration resistance of sands : R. C. Joshi, G. Achari, S. R. Kaniraj & H. Wijeweera, Canadian Geotechnical Journal, 32(5), 1995, pp 767–782

Effect of aging on the penetration resistance of sands : R. C. Joshi, G. Achari, S. R. Kaniraj & H. Wijeweera, Canadian Geotechnical Journal, 32(5), 1995, pp 767–782

Effect of aging on the penetration resistance of sands

The main objective of this study was to understand the effect of aging on the penetration resistance of freshly deposited sands. Two types of sand, locally available river sand used as masonry sand and Beaufort Sea sand, were selected for the study. The sands were allowed to age under a constant stress of 100 kPa in a specially designed apparatus in a dry state, as well as submerged in distilled water and in simulated sea water. Penetration resistance of the sand beds was measured periodically by pushing 4 probes into the sand bed. Mineralogical and fabric studies on freshly deposited and aged sand samples were conducted to detect the effect of aging, if any, on sand grains. The results indicate that aging significantly increases the penetration resistance of sands. The rate of increase in penetration resistance was higher for the submerged sand as compared with the dry sand. The increase in penetration resistance of the sand in a dry state was attributed to rearrangement of sand grains. In the submerged state, besides the rearrangement of sand particles, partial cementation caused by precipitation of salts and probably also silica on the sand grains and in the pores resulted in the larger increase in the penetration resistance. Key words : sand, aging, penetration resistance, freezing and thawing, sea water, distilled water.

Stiffness and Penetration Resistance of Sands versus State Parameter

Normalized small strain Young and shear moduli of pluvially deposited predominantly silica Ticino sand are well correlated against the state parameter as defined by Been and Jefferies. The same holds true for normalized cone resistance measured during the calibration chamber tests performed on the same test sand. It is shown that also parameters obtained from other kinds of penetration tests are correlatable against the state parameter of a sand. These findings might indicate a way to rationalize the correlations between penetration resistances and stiffness of sands being the latter referred to the preyield behavior of a sand.

Effect of Cementation on the Cone Penetration Resistance of Sand: A Model Study

Abstract A laboratory study was conducted to investigate the effect of cementation on the cone penetration resistance of sand. A new apparatus to form homogeneous artificially cemented sand specimens as well as uncemented ones, and a miniature quasi-static cone penetrometer were developed. Artificially cemented specimens with 1 and 2% cement content and relative densities ranging from 18 to 80% were tested. The penetration resistance of the cemented specimens was compared with those of comparable uncemented specimens. The influence of cement content and relative density of the specimens on their quasi-static cone penetration resistance was studied. The results indicate that cementation has a pronounced effect on the penetration resistance of sand.