A 5 meter thick clay layer has the following properties: p'=80 kPa, CR=0.04, RR=0.01, Ysat =...

  

Transcribed Image Text:

A 5 meter thick clay layer has the following properties: σp'=80 kPa, CR=0.04, RR=0.01, Ysat = 18 kN/m³, c₁ = 0.026 m²/month. This clay layer overlies a sand layer. Groundwater level is at the ground surface. A building will be construcled on this soil. The building is large enough to assume one-dimensional consolidation. The construction will take exactly 1 year. during which the load can be assumed to increase linearly with time, starting from 0. When completed, the building will apply 180kPa additional stress to the soil. a) Plot the variation of over-consolidation ratio with depth, before construction. b) Calculate the average degree of consolidation for this layer at 1.5 years after the end of construction. c) Calculate the consolidation settlement at 1.5 years after the end of construction, relative to the beginning of construction. Do not divide the clay into sublayers. d) Calculate effective stress at depths of 0, 1, 2.5, 4 and 5 meters at 1.5 years after the end of construction. Plot the effective stress distribution with depth, at t. e) Calculate the hydraulic gradient due to consolidation at the depth of 1 meter at 1.5 years after the end of construction. What is the direction of flow? A 5 meter thick clay layer has the following properties: σp'=80 kPa, CR=0.04, RR=0.01, Ysat = 18 kN/m³, c₁ = 0.026 m²/month. This clay layer overlies a sand layer. Groundwater level is at the ground surface. A building will be construcled on this soil. The building is large enough to assume one-dimensional consolidation. The construction will take exactly 1 year. during which the load can be assumed to increase linearly with time, starting from 0. When completed, the building will apply 180kPa additional stress to the soil. a) Plot the variation of over-consolidation ratio with depth, before construction. b) Calculate the average degree of consolidation for this layer at 1.5 years after the end of construction. c) Calculate the consolidation settlement at 1.5 years after the end of construction, relative to the beginning of construction. Do not divide the clay into sublayers. d) Calculate effective stress at depths of 0, 1, 2.5, 4 and 5 meters at 1.5 years after the end of construction. Plot the effective stress distribution with depth, at t. e) Calculate the hydraulic gradient due to consolidation at the depth of 1 meter at 1.5 years after the end of construction. What is the direction of flow?