5) What are the types of excavation hazard?

6) What is a Cave-In hazard and What are the causes of Cave-In hazard in excavation?

8) What are the fall protection safety requirements?

9) What types of Accidents might happen in Scaffolding?

Three different anchor bolts were installed in a 12" -2500 PSI concrete strength slab. The bolts were all 1/2 diameter with 6" embedment depth. The types were mechanical, epoxy, and cast in place during original pour.

which anchor bolt would you predict would take the greatest force to pull out from the slab and why

Explain does why:

• On the basis of qual workability the surface characteristics of aggregate have a limited impact on the ultimate strength of concrete.

• the surface characteristics of aggregate have a clear impact on ultimate strength of concrete on the basis of qual water content.

• The cylinder strength is higher than that of cube's.

• The aspect ratio of concrete cylinders has no impact on compressive strength obtained in compression testing machine with brush platens.

• Concrete bridges should not be subjected to stress levels higher than 0.55 of ultimate strengths.

• the maximum aggregate size of aggregate have two opposing effects on concrete strength.

In a pumping test of a confined aquifer, the steady state water level in an observation well 10m from the pumping well was 38mOD and was 42 mOD in another observation well 100m from the pumping well. The water levels in both wells were steady at 50mOD before the test began and then water was pumped at a constant rate of 0.005m^3/s from the pumping well.

Estimate the aquifer transmissivity.

If the aquifer is 15m thick, estimate the hydraulic conductivity of the aquifer material

A third well in the same aquifer is 1000m away from the pumping well. Estimate the steady state drawdown in that well due to pumping

Why will this test not give a value for the storativity of the aquifer?

a reinforced concrete bearing wall supports a 12" wide beam bearing in the full width of the wall spaced 10' o.c. . The bottom of the wall is a fixed connection. the top of the wall is a pinned connection. The wall is 20' tall. The load from each beam, Pu is 30 kips. Determine whether a 10" wall will work for this condition. select vertical and horizontal reinforcing steel.

Pipe Diameter(D)=150mm, Pipe Length(L)=980m, Friction factor(lambda)=0.05, Water level(h)=18m

(i) Neglecting minor losses plot the pipeline characteristic curve (system curve), for a flow rate range of 10-60 m3 /hr.

(ii) For an average flow of 20 m3 /hr select a suitable pump from the pump performance charts provided.

(iii) What are the discharge and head values you would record at duty point for the selected pump?

1. Based on the following test data and batch ticket information,

(1) calculate the concrete density and yield

(2) determine whether it is under yielding or over yielding

(3) make a sand (s.g.=2.63) adjustment if under yielding

(this problem requires some critical thinking since it is a bit more complicated than the example in lecture note 13)

Test data:

Weight of the bucket with concrete:             44.72 lbs

Weight of the bucket:                                     7.98 lbs

Volume of the bucket:                                    0.249 cubic feet

Material batched:

Sand:                                                               10,010 lbs

¾” Rock:                                                         12,000 lbs

Cement:                                                          3,530 lbs

Fly Ash:                                                          600 lbs

Air:                                                                 5%

Water:                                                             124 gallons

Quantity ordered:                                            7 cubic yards

(however, yield should be check with one cubic yard)

The mix was designed as 27.1 cubic feet per cubic yard.

Why is it important to coordinate at time of bid and what are the downsides to coordinating at the time of bid?

Does cavitation occur when the NPSHa (Available Net Positive Suction Head) is below or above the pump's NPSHr (Required Net Positive Suction Head)? Explain.

1. 1. In building a profile for a set of sequences, PSI BLAST weighs sequences differently. Why is this done?
2. 2. What are pseudocounts and why are they used?

A water with a pH =7.0 has been analyzed and found to have the following composition, with all concentration in mg/L as CaCO3:
CO2 = 125 mg/L
Ca2+ = 250 mg/L
Mg2+ = 80 mg/L
Fe2+ = 10 mg/L
Alkalinity = 260 mg/L
SO4 2- = 50 mg/L
Cl- = 30 mg/L
a) what is the hardness of this water? Report in mg/L as CaCO3
b) use the excess Lime soda Ash method and estimate the kilograms of lime and kilograms of soda Ash that will be needed per 1MGD to soften this water. Report assumptions used in the calculations.

You have a nominal 3-inch diameter steel pipe, 15 feet high that is embedded into a concrete foundation. Neglecting the weight of the column, answer the questions below:

A. What is the maximum vertical load this pipe can support/critical load (#)?

B. If a vertical load of 2,000#s and a horizontal force of 100#s are applied at the top of the column, what are the maximum combined tensile and compressive stresses (psi) where the column meets its foundation? Are they allowable?

Parameter Steel .

Modulus of Elasticity 30,000,000 psi

Proportional/Elastic Limit 34,000 psi

Allowable Bending Stress 24,000 psi

Allowable Axial (C or T) Stress 24,000 psi

Allowable Shear Stress 16,500 psi

Wall thickness 0.216in of pipe

What is the condition that hazard takes place (1 mark). List any four principles of hazard control (2marks). Write a short note on crushing hazard and use of machine guard (2marks).

There are many operations in oil and gas industry such as drilling, casing, cementing, perforation, well logging and well stimulation. Mention the possible hazard (2.5 marks) and safety measures (2.5 marks) that an engineer must keep in mind during cementing operation.