LARGE-STRAIN UNDRAINED PRESSUREMETER INTERPRETATION BASED ON LOADING AND UNLOADING DATA

Traditionally pressuremeter tests results are interpreted using only t he loading pressure-expansion data. An interpretation method has been developed that makes use of both the loading and unloading portions of a pressuremeter test and incorporates nonlinear, undrained soil behav iour. This method has been modified to handle large strains. The propo sed interpretation accepts that some level of soil disturbance exists during the early stages of a pressuremeter test, and hence more emphas is is placed on the unloading portion of the test. A methodology is de scribed to allow this interpretation procedure to be applied to self-b ored, prebored, and full-displacement undrained pressuremeter tests. T he proposed method is evaluated using self-boring and full-displacemen t pressuremeter test results from various published field projects. Th e interpretation is accomplished using commercially available microcom puter software that can perform the curve-matching process for both lo ading and unloading portions of the test.