CIVE 224 Soil Engineering Midterm Chap 1Chap 5 March 8th 201

CIVE 224 Soil Engineering Midterm (Chap 1-Chap 5) March 8th, 2018 14. The moisture content of soil at which the volume of soil mass ceases to change is (a) plastic limit. (b) shrinkage limit. (c) liquid limit. (d) Atterberg limit 15. According to the AASHTO soil classification, the general subgrade rating for soils of group A-4, A-5, A-6 and A-7 is (a) fair to excellent. (b) fair to poor. (c) excellent to good (d) excellent to poor 16. Which of the following soils has a highly complex structure? (a) Gravelly soil (b) Sandy soil (c) Silty soil (d) Clayey soil 17. The soil classification systems are mainly based on (a) grain-size distribution and plasticity of soils. (b) grain-size distribution and strength characteristics of soils. (c) plasticity of soils and strength characteristics of soils. (d) permeability, compressibility and strength characteristics of soil. 18. If the particle size distribution of a soil shows 309% sand, 40% silt and 30% clay-size particles, its textural classification is (a) clay loam. (b) loam. (c) silty clay loam. (d) silty clay. 19. The group index of soils is always (a) 0-100. (b) whole number (c) 0-1 (d) integar 20. When two soil samples got the same GI value, they (a) show same mechanical behavior (b) have same minerals. (c) belong to the same ASSHTO classification category. (d) None of the above is true.

Solution

Answer 14 :- (b) shrinkage limit

we know that after shrinkage limit the reduction in water content will not cause a decrese in the volume of the soil

Answer 15:- (b) fair to poor

according to AASHTO classification A-4 and A-5 is grouped as silty soil and A-6 and A-7 grouped as clayey soil and general rating of this group is fair to poor

Answer 16:- (d) clayey soil

we know that the more fine particle has the more complex structure and clayey soil has smallest particles (less than 0.002mm)

Answer 17:- (a) grain size distribution and plasticity of soil

in classification systen we are trying to find the size of soil particle and there plastic property

Answer 18:- (a) clay loam

in soil texture triangle a soil has 30% sand 40% silt and 30% clay has shows clay loam

Answer 19:- (b) whole number

the group index should be rounded off to the nearest whole number

Answer 20:- (c) belong to the same AASHTO classfication category

AASHTO classification is based on the GI value of soil so if tow sample has same GI value then they are in same category

( All answers are correct and best of my knowledge, if it helps you for your study then please give me a positive CF score i really need it)