158577
| Question | Answer |
| Requirements for the stability and safety of structures: | 1. Deformation (especially vertical deformation known as settlement) must be within a tolerable limit. 2) Shear strength of soil must be adequate to withstand the stress induced |
| Compression of soil caused by: | 1. Deformation of soil particles 2. Relocation of soil particles 3. Expulsion of water and/or air from the void spaces 4. Viscous deformation (creep) |
| Three types of settlement: | 1. Elastic (or immediate) settlement (Se) ‐Elastic deformation without change in moisture content ‐Occurs directly after application of load 2. Primary consolidation settlement (Sc) ‐Volume change in saturated soils due to expulsion of water from void spaces 3. Secondary consolidation settlement (Ss) ‐Rearrangement of soil particles in saturated cohesive soils under constant effective stress (creep) |
| Total settlement, S_T = | Se + Sc + Ss |
| One‐Dimensional Laboratory Consolidation Test | First suggested by Terzaghi Performed in a consolidometer (sometimes known as Oedometer) Soil specimen placed in a metal ring, with two porous stones (one top and one bottom) Specimen size: 64 mm (2.5 inch) dia, 25 mm (1 inch) thick Loads are applied using a lever arm Compression is measured using a dial guage Specimens kept is water Each load is kept 24 hours, after that load doubled At the end dry unit weight of the specimen is calculated |
| Normally consolidated: | Present effective overburden pressure is the maximum effective overburden pressure the soil was subjected ( = ’c) |
| Overconsolidated: | Present effective overburden pressure is less than the effective overburden pressure soil experienced in the past (’< ’c) |
Want to create your own Flashcards for free with GoConqr? Learn more.