STRUCTURE IIl, GEOTECHNOLOGY II AND CONCRETE TECHNOLOGY II KNEC PAST PAPERS

SECTION A: STRUCTURES D
Answer TWO questions from this section.
1. Figure 1 shows a Reinforced concrete retaining wall. The soil retained is a clayey gravelly sand with a horizontal surface. The soil properties are c’ = 0, <1> = 42°, = 18 KN/m?. Assuming that the water table is well below the base level, check the stability of the structure for each of the following:
(i) sliding:
(ii) overtuning;
(iii) bearing pressure.

(a) State Mohr’s theorems. (3 marks)
(b) Using Macaulay’s method, determine the slope and deflection at point C for the loaded beam shown in figure 2 in terms of EL

Design and detail the section of a slab simply supported on four sides of a 200 mm given the following information.
Internal dimensions of slabs – 4300 mm x 6100 mm
Thickness of slab – 220 mm
Live load – 10 KN/m2
Characteristics material strengths:
f* – 30N/mm2
f, – 460 N/mm?
Use the information in Tables 1,2,3 and 4. (20 marks)

SECTION B: GEOTECHNOLOGY IT
Answer TWO questions from this section.
4 (a) 0) With reference to weathering, explain the term weathering.
(ii) Explain the occurrence of chemical weathering and state six commonly occurring chemical weathering processes. (8 marks)
(b) Outline six types of geological maps. (9 marks)
(c) State three items of information represented on engineering geological maps.

5 (a) Describe two types of hard rock quarries. (5 marks)
(b) State the four operations considered in rock extraction. (4 marks)
(c) Blasting in quarries is controlled by the Quarries Regulations:
(i) Explain why the regulations are issued;
(ii) Outline three important requirements of these regulations with respect to blast managers. (8 marks)
State three drilling methods employed in quarrying stones. (3 marfe) (d) gs ploy quarrying
6 (a) State six purposes of dam construction. (6 marks)
(b) Explain three factors considered in the selection of a dam site. (9 marks)
(c) State five reasons for the construction of tunnels. (5 marks)

SECTION C: CONCRETE TECHNOLOGY 
 Answer ONE question from this section.
7. (a) Differentiate between precast and insitu concrete.
(b) State six advantages of precast concrete.
(c) Explain the difference between post-tensioning and pre-tensioning in prestressed concrete systems.
(d) Materials for fixing precast units form structural connections. Outline four requirements to be fulfilled by these connections.
8. (a) State five effects of hot weather on placing of concrete.
(b) Outline six precautions to be taken inorder to minimize the adverse effects of hot, weather in concreting.
(c) Outline four characteristics of functional joints in concrete.

(Visited 554 times, 1 visits today)
Share this:

Written by