1 A truck loaded with 2 m3 dry sand appears to weigh ”3 tons” more than the weight of the empty truck. What is the meaning of the term ”3 tons”, and what is then volumetric weight of the sand?
2 If it is known that the density of the sand particles in the material of the previous problem is 2600 kg/m3, then what is the porosity n? And the void ratio e?
3.3 It would be possible to ﬁll the pores of the dry sand of the previous porblems with water. What is the volume of the water than the sand could contain, and then what is the volumetric weight of the saturated sand?
4 The soil in a polder consists of a clay layer of 5 meter thickness, with a porosity of 50 %, on top of a deep layer of stiﬀ sand. The water level in the clay is lowered by 1.5 meter. Experience indicates that then the porosity of the clay is reduced to 40 %. What is the subsidence of the soil?
5 The particle size of sand is about 1 mm. Gravel particles are much larger, of the order of magnitude of 1 cm, a factor 10 larger. The shape of gravel particles is about the same as that of sand particles. What is the inﬂuence of the particle size on the porosity?
6 Determine from Figure 3.3 the volume of the soil on the bottom of the measuring glass, and also read the increment of the total volume from the rise of the water table. What is the porosity of this soil?
7 A container is partially ﬁlled with water. A scale on the wall indicates that the volume of water is 312 cm3. The weight of water and container is 568 gram. Some sand is carefully poured into the water. The water level in the container rises to a level that it contains 400 cm3 of material (sand and water). The weight of the container now is 800 gram. Determine the density of the particle material, in kg/m3