Effects of Back Pressure and Strain Rate Used in Triaxial Testing of Stabilized Organic Soils and Clays

Abstract

In deep stabilization of soft soils in Sweden, dry binders such as cement and quicklime are normally used. Mixing dry binders into the soils will lead to a lower degree of saturation than that of the unstabilized soils, which normally are fully saturated before stabilization. In triaxial testing of stabilized soils, the applied back pressure chosen for the tests may affect the degree of saturation and in turn also the results obtained. A number of triaxial tests have been performed using different back pressures in order to study the effect on measured shear strengths of stabilized organic soils and clays. The effect of rate of strain on the strength of stabilized organic soils was also studied in a series of tests. The results show that in particular the chosen back pressure can greatly affect the strength of stabilize soils, although the rate of strain can also exert an influence on the measured strength.

Behavior of braced excavation supported by panels of deep mixing columns

“…16d) was considerably lower compared to the same column in Test 1.This can be attributed to the higher area improvement ratio in Test 1. One possible explanation for the observed pore pressure response is that improved soil is heterogeneous and is in most cases not fully saturated due to the manufacturing process where the dry binder is supplied and mixed with the in situ soil under high air pressure (Baker 2000;Åhnberg 2004). 15 In the LC-panels Δ‫ݑ‬ was measured only through the piezometers integrated in the EPC and the results could not be confirmed.…”