Sand Samples Collected for the Present Study

Một phần của tài liệu Modeling Three-Dimensional Shape of Sand Grains Using Discrete El (Trang 50 - 55)

A wide variety of natural and processed sand samples having different roundness and angularity are collected from various locations around the world in conjunction with the current study. The intent was to obtain materials from as wide a geographical coverage as possible so that they would be more likely to be different in mean grain size, size

distribution, and morphology due to differences in the deposition process. The sand samples collected for the current study encompass natural sands from beaches, rivers, dunes and manufactured crushed sands. The two-dimensional projection images of the sand samples collected for the study are documented in Appendix A.

3.1.1 Sample Selection Procedure

A detailed description of different sand samples obtained from various sources in the literature and their engineering properties such as gradation (mean grain size, uniformity coefficient, coefficient of curvature), packing (minimum and maximum void ratio and dry density) are documented in the form of a spreadsheet. These parameters can be a useful source for selecting materials for the present study. Figure 3.1 through Figure 3.8 present the variation of minimum and maximum void ratio for different types of sand samples.

0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

e max e min

Kogyuk Erksak Syncrude TS Toyoura

Leighton Buzzard Massey Tunnel Monterey Alaska Nerlerk Ticino Blasting sand Glass beads Cambria Hokksund

Chattahoochee River Medium grained Silica Chiba

Mersey River

Figure 3.1 Variation of Minimum and Maximum Void Ratio (Group # 1)

0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

e max e min

Crushed Silica Brasted River Portland River Chonan Silty Kiyosu Lagunillas Lornex Tia Juana Silty Hostun RF Brenda Kizugawa Echigawa Abashiri Tottori Sado Sumaura Nevada Sydney Ottawa

Santa Monica sand Likan sand

Figure 3.2 Variation of Minimum and Maximum Void Ratio (Group # 2)

0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

e max e min

Douglas Lake Calcareous, Gujarat Ganga sand Kalpi sand Glazier Way sand Mortar sand Agsco sand Jebba sand Colorado sand Quiou sand Cositas dam sand Till sand LSF dam sand Lytle sand, colorado Enewetak coral sand Sacramento river sand Hokksund sand Karlsruhe sand Yatesville sand Fontainebleau sand Daytona Beach sand Michigan Dune sand

Figure 3.3 Variation of Minimum and Maximum Void Ratio (Group # 3)

0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

e max e min

Yurakucho sand Kenya sand Catania sand Dog's Bay sand Kingfish sand Halibut sand Ballyconneely sand Bombay Mix sand Amami sand Mol sand Berlin sand Chengde sand Chiibishi sand Sao Paulo sand Oklahoma sand Banding sand Ham river sand Fraser river sand Loire River sand Mailiao sand

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

0 0.2 0.4 0.6 0.8 1 1.2

e max - e min e max

Kogyuk Syncrude TS Toyoura Massey Tunnel Monterey Sacramento River Nerlerk

Ticino Blasting Sand Glass Beads Cambria Sand Hokksund Banding

Chattahoochee River Medium grained silica Chiba

Portland River Ottawa

Figure 3.5 Variation of Maximum Void Ratio with emax - emin (Group # 1)

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

0 0.2 0.4 0.6 0.8 1 1.2

e max - e min

e max

Nevada Crushed Silica Chonan Silty Fraser River Kiyosu Lagunillas Lornex Tia Juana Silty Hostun RF Brenda Kizugawa Echigawa Tottori Sado Sumaura Alaska

Leighton Buzzard Erksak sand

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

0 0.2 0.4 0.6 0.8 1 1.2

e max - e min e max

Douglas Lake Calcareous, Gujarat Ganga sand Kalpi sand Glazier Way sand Mortar sand Agsco sand Jebba sand Colorado sand Quiou sand Cositas dam sand Till sand LSF dam sand Lytle sand

Enewetak coral sand Mersey river Sydney sand Ham river sand Abashiri sand Fontainebleau sand Santa Monica sand Likan sand

Daytona Beach sand Michigan Dune sand

Figure 3.7 Variation of Maximum Void Ratio with emax - emin (Group # 3)

0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1

0 0.2 0.4 0.6 0.8 1 1.2

e max - e min

e max

Yurakucho sand Kenya sand Catania sand Karlsruhe sand Dog's Bay sand Kingfish sand Halibut sand Ballyconneely sand Bombay Mix sand Amami sand Mol sand Berlin sand Chengde sand Chiibishi sand Sao Paulo sand Oklahoma sand Brasted river sand Yatesville sand Loire River sand Mailiao sand

Figure 3.8 Variation of Maximum Void Ratio with e - e (Group # 4)

Granular packing is represented by the void ratio of the assembly and the shear strength behavior of soil is influenced by the packing density of the granular mass (Holtz and Kovacs, 1981). The maximum and minimum void ratios of a soil mass depend on the shape of the individual grain and grain size distribution. Research had been documented in the literature describing the relationship between void ratio and angle of internal friction of cohesionless soil and the studies suggested an increase of maximum (emax) and minimum (emin) void ratio and void ratio difference (emax – emin) with increasing particle angularity or decreasing roundness and sphericity (Youd, 1973; Cho et al., 2006; Fraser, 1935). Based on several experiments published in the literature, a decrease in void ratio results in an increase in angle of shearing resistance (φ) and therefore an increase in shear strength of granular soil mass (Zelasko et al., 1975; Shinohara et al., 2000).

Materials can be selected based on the above figures. For example, Chiba, Alaska, medium grained Silica, Lagunillas, Kizugawa, crushed Silica, Quiou, Jebba, Colorado, Till, Ganga, Glazier Way, Dog’s Bay, Kenya, Ballyconneely, Kingfish, Sao Paulo, Oklahoma, Erksak, Leighton Buzzard sands can be some of the interesting materials to study since their void ratios fall a way above or a way below on the plot. Though it was intended to acquire these materials for the purpose of the present study, it was difficult to obtain all these materials from different parts of the world. Instead, the materials

collected for the current study are easily available, but still cover a wide range of

geographic locations and have various degrees of angularity and roundness. Therefore, it is expected that they are likely to be different in grain size, shape, mineralogical

composition and other engineering properties. The properties of sand samples collected for this study are presented next.

Một phần của tài liệu Modeling Three-Dimensional Shape of Sand Grains Using Discrete El (Trang 50 - 55)

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