IMPROVEMENTS IN OR RELATING TO THE DETERMINATION OF DEFORMABILITY AND RESIDUAL STRESS OF SOIL AND ROCK FORMATIONS

摘要

1,223,342. Testing rock or soil. LABORATORIO NACIONAL DE ENGENHARIA CIVIL. May 3, 1968 [May 6, 1967], No.21087/68. Headings G1N and G1S. To minimize disturbance of in situ soil or rock at a to be exposed face of the soil or rock when the deformability and residual stressing of the soil or rock is to be determined by observing or applying tests to the face a narrow slot or contiguous narrow slots are formed in the soil or rock to expose the required face. The or each slot is cut by a large diameter, diamond tipped disc 9 supported in the bifurcated lower end of a tubular support 11 slidable along an upright column 2 of a frame 1 bolted to rock adjacent the slot being cut. The support 11 may be reciprocated or oscillated laterally of the column 2. To permit of slots of depths greater than the radius of the disc being cut in rock a bore greater than the diameter of the support 11 may be drilled in the rock to allow for passage of the support into the rock when deep slots are to be cut. Segmental fillers may be inserted in any so formed bore to allow of flat surfaces being presented to flat, pressure-applying pads when inserted into the slot or slots to stress the soil or rock to be tested. Such a pad 14 may be formed by securing two dished plates together around their contacting edges and will be provided with a nipple 16 to allow of pressurized air being entered into the pad and means 17 for allowing the passage of electric cables from strain gauges 19 secured between the plates within the pad out of the pad.