Advanced Triaxial Testing of Soil and Rock

Abstract

Description First publication of its kind in 25 years, this 900-page volume serves as an engineer’s guide for triaxial testing. Subjects include: equipment, test methods, and test interpretation and errors, and new test varieties.

Stress-dependent undrained shear behavior of remolded deep clay in East China

“…An approximate theoretical strain rate which is sufficiently slow for the pore pressures across the specimen with fully effective drains (using filter strips) to reach 95% equalization 1 can be estimated by 1 The degree of equalization is (1−p/p 0 ), where p 0 is the difference in pore pressure between the middle and ends of the specimen at a given strain with no redistribution, and p is the difference in a test taking a time t to reach this strain (Bishop and Henkel, 1962) the following equation (Germaine and Ladd, 1988;Bishop and Henkel, 1962):…”

“…where ε f is the axial strain at failure, h is the 1/2 height of the specimen, and C b can be taken from oedometer data although it is not strictly equal to the coefficient of normal consolidation C v from an oedometer test (Germaine and Ladd, 1988). The shear strain rate calculated by Eq.…”

“…End friction and axial strain rate have little effect on the effective strength parameters (Hight, 1982), especially for normally consolidated soil (Germaine and Ladd, 1988). Moreover, the end platen and axial strain rate in the tests are the same for each one of the four clays.…”

Simulation of Stress Paths Derived from FEM Analysis in Triaxial Tests

“…5. This means, that if the stress level, defi ned as (9): (9) , f q q SL and determined in the numerical analysis, is to be simulated during the laboratory test, then to stay at the compression plane, the equivalent stress should be modifi ed to: (10) . …”

“…So far, the full control of all the three principal stresses (magnitudes and rotations) in laboratory conditions is possible practically only in a hollow cylinder apparatus, which, unfortunately is in possession of only a few university centres and still is not free from some technical limitations, like: non-uniformity of stresses or cumbersome preparation of specimens (Hight et al [9], Saada [10]). …”