3 What is a tremie 4Describe soil settlement because of lowe

3- What is a tremie?

4-Describe soil settlement because of lowering groundwater?

5-What is the variable \"k\" and its definition?

6- How is \"k\" obtained in the lap?

all answers must be typed

Solution

3) Tremie is the technique which have been used for placing concrete under water.In tremie method uses a pipe through which concrete is placed below water level.The bottom end of the pipe is kept immersed in fresh concrete so that the rising concrete from the bottom displaces the water without washing out the cement content

4) If the Ground water table falls then effective stress and pore water pressure decreses but effective stress increases and if the Ground water table rises then effective stress and pore water pressure increases but effective stress decreases so lowering of the groundwater table cause the soil to consolidate, which induces settlement. With softer, more compressible soils, settlements can become large.So Lowering of the groundwater table can cause the soil to consolidate, which induces settlement.

5) k is coefficient of permeability or hydraulic conductivity.which can be defined Property of a soil which permits the flow of water (or) property of a porous material which permits the passage or seepage of water through its interconnecting voids

6)k obtained from the laboratory by 4 methods those are

a) Constant head methd:-Best for corase grained soil

b) Variable head method:-Best for fine grained soil

c) Capillarity permeability test:-Best for partially saturated soil

d)Consolidation test :- Best for impermeable clay