| Summary: In this thesis horizontal stress transformations of rocks and clay-silt size particular materials are investigated. There are 4 main topics of thesis. First is stability analysis for circular underground openings that is excavated in elastic rock zone. An approach about yield zone (plastic zone) thickness is derived in respect of Bray and Brown stress influence ratio and stress distribution formulas, Kirsch formulas and Mohr-Coulomb failure criteria. Ratio of horizontal stress/vertical stress (k ratio) effects stress distribution and durability of underground openings, directly. Plastic zone’s vertical thickness increases with increasing k ratio and it decreases with decreasing k ratio. Plastic zones expand in horizontal direction with decreasing k ratio. In the second part, polymer fiber reinforced and unreinforced shotcrete supports are compared as tunnel support. Polymer fiber effects are investigated in respect of compressive, flexural strengths and stiffness of support. Poisson ratio and elasticity modulus effect the stiffness of support. Polymer fiber addition decreases the poisson ratio, elasticity modulus and stiffness of shotcrete. Durability of two steep foundation excavation in urban place of Trabzon is investigated with in-situ and laboratory works. And, one of them is evaluated as risky. And, retaining wall construction is suggested for this steep soil layer. Necessary horizontal support pressure is calculated. Paste backfill barricades and exposed horizontal stress for barricades are investigated in fourth part of thesis. Barricade designing fundamentals are referred. Two new barricades were designed for Cayeli Copper Mine paste backfill aplications. Details of new designs are explained. |
