A structural steel beam connection requires 6 high-strength bolts, each with a shear capacity of 21.6 kips. If the connection must resist a factored shear load of 95 kips, what is the utilization ratio of this connection?
Correct Answer
C) 0.73
Total connection capacity = 6 bolts × 21.6 kips/bolt = 129.6 kips. Utilization ratio = Applied load ÷ Capacity = 95 kips ÷ 129.6 kips = 0.73 or 73%. This indicates the connection is adequately designed with reasonable reserve capacity.
Why This Is the Correct Answer
Total bolt capacity = 6 × 21.6 = 129.6 kips. Utilization ratio = applied load ÷ capacity = 95 ÷ 129.6 = 0.733, which rounds to 0.73. A ratio below 1.0 confirms the connection is adequate, and 0.73 indicates roughly 27% reserve capacity — a sensible design margin for high-strength bolt groups.
Why the Other Options Are Wrong
Option A: 0.92
0.92 would result from dividing 95 by approximately 103, not the correct 129.6 kips total capacity. This likely comes from using only 4–5 bolts in the calculation or misapplying a capacity reduction factor that is not part of this problem.
Option B: 0.85
0.85 would require a total capacity of about 111.8 kips, meaning the student may have accidentally used ~18.6 kips per bolt rather than the stated 21.6 kips, or miscounted the bolt group size.
Option D: 1.05
1.05 is greater than 1.0, which would indicate an overloaded (inadequate) connection. This answer results from dividing 95 kips by only 90.3 kips — essentially computing capacity using just 4 bolts at 21.6 kips each — a miscalculation of the bolt group.
Memory Technique
Think of utilization ratio as 'how full is the bucket?' — your load is the water you're pouring in; your total bolt capacity is the bucket size. 95 kips poured into a 129.6-kip bucket is 73% full (0.73). If you overfill (>1.0), the connection fails.
More NASCLA Questions
Which AIA document contains the general conditions that govern the rights and responsibilities of all parties in a construction contract?
A construction company has direct labor costs of $85,000, direct materials of $120,000, and overhead costs of $45,000 for a project. What is the total job cost?
What is the primary purpose of job cost accounting in construction?
A construction company has current assets of $350,000 and current liabilities of $280,000. What is the company's working capital?
In CSI MasterFormat, which division covers earthwork and site preparation?
In a mechanical drawing, what does 'CFM' typically measure?
In CSI MasterFormat Division 08, which of the following would typically be included?
On a mechanical plan, what does the symbol 'RTU' typically indicate?
What is the minimum preheat temperature for welding ASTM A992 steel when the ambient temperature is 15°F?
A general contractor's balance sheet shows total assets of $850,000, current liabilities of $320,000, and long-term debt of $180,000. What is the company's equity?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass