DEPARTMENT OF AGRICULTURE AND BIO - ENVIROMENT ENGINEEING TECHNOLOGEY

CEC 122: SOIL MECHANICAS

FIRST SEMESTER AXAMINASTIONS

QUESTION (1)

(a) What do you understand by the term soil compaction?(b) Why is soil compaction necessary in project construction?(c) Differentiate between soil compaction and soil consolidation

Question (2)

List and briefly explain the factors affecting soil compaction.

Question (3)

Defined the following

(i) soil density (ii) wet density (iii) dry density of soil (iv) optimal moisture content of soil (OMC)(v) maximum dry density of soil (MDD)(vi) soil bearing capacity

Question (4)

(a) What is field compaction?(b)What is the aim of field control test.?

(c)What is the end – uses at field control test?

QUESTION (5)

Write short note on the following:

(1) Unsuitable soil materials in the field (2) Cut to spoil soil materials in the field (3) Cut to fill soil materials (4) Borrow to fill soil material in the field.

Question (6)

Write the require steps for a common control field test

QUESTION (7)

(a) What do you understand by about compacting equipments?

(b) List and explain the three (3) actions involved in compaction with its equipment.

QUESTION (8)

In a road construction project arrowed engineering complex, a borrow to fill materials have the following parameters:

Weight of the material ₌ 3369 g Volume of the materials ₌2225mm3 Number of layers ₌ 3 Weight of hammer used ₌ 2.5 kg Hammer drop distance ₌ 30 cm Number of blows ₌ 61 Mould size ₌ (2225mm3)

(a) What is wet density of the material?

(b) What is the comp active effort of the material?

QUESTION (9)

(a) List the three comp active test reference standard you known,.List the comp active requirement tests and explain.

QUEATION (10)

Define the following;

I. Liquid limitII. Plastic limit

III. Plasticity index IV. Relative compactionV. Well grade soil

VI. Poor grade soil

QUESTION (11)

(a)What is California bearing ratio (C.B.R?)

(b) What are specifications standard for

I. Sub gradeII. Sub base

QUESTION (12)

A) Field density test is performed by the balloon method. The following data were obtained from the test;

–Mass of soil removed pan=1590g

–Mass of pan =125g

–Initial balloon reading =538cm3

–Final balloon reading =1288cm3

i) Calculate the wet density

Water content information;

–mass of wet soil +pan =404.9g

–mass of dry soil + pan =365.5g

–mass of pan =122.0g

ii) Calculate the dry density of the material.

QUESTION (13)

A) What are end-product specifications?

b) What do you under standard by method specification?

QUESTION (14)

a) What are the admixtures to improve the shearing strength of the following material?

I. AsphaltsII. Concrete

III. Clay

b) What is the type of comp active equipment used for the compaction of the following materials?

I. AsphaltsII. Concrete

III. clay

QUESTION (15)

Briefly explain how to achieve compaction from End-products specification to method specification.

COURSE CODE102

QUESTION (8)

a) What is tachymetry?b) What is the primary objective of tacheometric survey?c) Why tacheometry is preferable chaining on rough ground?

(9)a) Why chaining is preferable on a flat grounds to tacheometry?b) What are the uses of tacheometric survey?

(10)

a) What is a vertical angle?b) What is the instrument used in measuring vertical angle?c) What is the difference between zenith angle and vertical angle?

(11)

a) What do you understand by permanent adjustment?b) What are the important points in measuring vertical angles?

(12)

Explain the following

i. Horizontal distanceii. Vertical distance

iii. Reduced leveliv. Stadia linesv. Angle of elevation

vi. Angle of depression

(13)

a) What do you understand by instrumental errors?b) Explain the field errors involved in stadia tacheometry.

(14)

The following readings were taken on a vertical staff with a tacheometer fitted with an anallatic lens and having a constant of 100.

Staff station Bearing Stadia Reading Vertical angleLower Middle Upper

A 27°30´00ˮ 1.000 1.515 2.025 +8°00´00ˮB 207°30´00ˮ 1.000 2.055 3.110 -5°00´00ˮ

Calculate the relative levels of the ground at A. and B, and the mean slope between the two point (A & B).

(15)

Differentiate between theodlite and total station?