EXPERIMENTAL STUDY OF PRINCIPAL STRESS VARIATION EFFECT AT TRUE TRIAXIAL TEST ON BANDUNG SOFT CLAY STRESS DEFORMATION BEHAVIOUR

• Main Author: KURNIAWAN, RAHMAT
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30147
• Institution: Institut Teknologi Bandung

<p align="justify">The influence of the intermediate principal stress is often ignored in the determination of soil stress deformation behaviour for the commonly used method of simplification of the model under conditions of two-dimensional or plane strain. In actual field conditions, soils receive the load in the direction of three dimensions and undergo stress rotation direction to reach a stable condition. So as to obtain soil behavior in accordance with the actual conditions in response to the required load deformation testing by considering the influence of the intermediate principal stress and principal stress rotation. Laboratory apparatus capable of involving three directions is True Triaxial. <br /> <br /> Bandung soft clays, taken from Gedebage, have silty clay type with a high plasticity condition. To determine the stress deformation behaviour of Bandung soft clays, in this study conducted five (5) principal stress variations (b) within two (2) direction of principal stress rotation (?). Giving principal stress variation (b) is intended to look at the effect of an increase in intermediate principal stress with an increase in major principal stress and towards giving pressure horizontally or vertically on the characteristics of shear strength (c and ?) and stiffness modulus (E50), the increase in pore water pressure (Af) and models that fit the failure criteria of Bandung soft clays stress deformation behavior. Effective shear strength (?') increases with increasing stress variation (b) up to 10% in the increment of intermediate principal stress 0.5 times to the major principal stress. Giving load with principal stress rotation changed from 0 (zero) degrees to 90 (ninety) degrees produces a decrease in undrained shear strength ( ? ) up to 15%. The stiffness modulus and the Skempton Af parameter also increased against the increase in voltage variation, the loading in the lateral compression direction (? = 90?) resulted in higher the Skempton Af parameter. The failure criterion in accordance with True Triaxial test results from Bandung soft clay is the Extended Tresca model.<p align="justify"> <br />