Geoscience Reference
In-Depth Information
(a) Stress-strain
diagram.
(b) Stress-path
diagram.
Fig. 15.14. Loading of sequence 1on isotropically consolidated sand specimen.
(a) Stress-straindiagram. (b)Stress-path diagram.
(Sendir et al., 2006; Wassan et al., 2006) are compared in Figures15.14 and 15.15. For
these tests, specimens of Toyoura sand were consolidated isotropically under 50kPa and
wereshearedinatorsionsheardevice.Thesamplesizewas10cminouterdiameter,6cm
in inner diameter, and 20cm in height. It is evident that sequence 3 produced more pro-
found effects onsand such as greater shear strainand higher excess pore water pressure.
ThedensificationeffectsofdifferentsequencesofblastingareexaminedinFigure15.16.
Itisshownhereinthatsequence3producesthegreatestvolumetricstrainupondissipation
of generated excess pore water pressure. Therefore, it may be stated that the efficiency
of soil improvement can be improved by considering the sequence of blasting and with-
out increasing the amount of explosive resources. Note further that the present study is
limitedtoatwo-dimensionalconsiderationofblastingsequences(Figure15.8).However,
a similarapproach to the problem is possible.
