PROBLEM 4- Figure (A) shows a water storage tank with a cross-braced, four-leg tower. Neglect the weight of the steel frame. Assume • Frame to be identical to N-S/E-W elevations. • Full height columns (no splice) • Pinned ends at diagonals, struts, and columns. • Elastic design • Use El-Centro Response Spectrum for your analysis. Required A. find critical axial loads and columns due to the seismic overturning moment. B. find maximum axial forces in upper and lower struts and diagonals. (assume compression diagonals are not acting). 24 12' 12' W = 40 k W = 40 k Tank Ground Elevation Fig. 4 (a) Plan-Elevation View 4' 12' 12' RESPONSE SPECTRUM IMPERIAL VALLEY EARTHQUAKE MAY 18, 1940 - 2037 PST IIIA001 40.001.0 EL CENTRO SITE IMPERIAL VALLEY IRRIGATION DISTRICT COMP SOOE DAMPING VALUES ARE O. 2. 5. 10 AND 20 PERCENT OF CRITICAL 400 200 F80 Acceleration, g 80 60 40 8884 100 20 20 086 4 VELOCITY (in./sec) .8 201 02 800 006 004 002 الله 2 86 Displacement, in. -20 400 008- 600 400 200 60 200 100 80 60 -800 40 20 20 006 004+ 10 986 F2000 4 2 0013 8000 0006 0004 .8 .6 2 4 6810 PERIOD (secs) .1 .04 .06.08.1 .2 4 .6.81 20 4 2 20 20

A column in a building is subjected to the following load effects: 9 kips compression from dead load 5 kips compression from roof live load 6 kips compression from snow 7 kips compression from 3 inches of rain accumulated on the roof 8 kips compression from wind a. If lead and resistance factor design is used, determine the factored load (required strength) to be used in the design of the column. Which AISC load combination controls? b. What is the required design strength of the Column? c. What is the required nominal strength of the column for a resistance factor of 0.90? d. If allowable strength design is used, determine the required load capacity (required strength) to be used in the design of the column. Which AISC load combination controls? e. What is the required nominal strength of the column for a safety factor of 1.67?

A beam must be designed to the following specifications: Span length = 35 ft Beam spacing = 10 ft 2-in. deck with 3 in. of lightweight concrete fill (wc=115 pcf) for a total depth of t=5 in. Total weight of deck and slab = 51 psf Construction load = 20 psf Partition load = 20 psf Miscellaneous dead load = 10 psf Live load = 80 psf Fy=50 ksi, fc=4 ksi Assume continuous lateral support and use LRFD. a. Design a noncomposite beam. Compute the total deflection (there is no limit to be checked). b. Design a composite beam and specify the size and number of stud anchors required. Assume one stud at each beam location. Compute the maximum total deflection as follows: 1. Use the transformed section. 2. Use the lower-bound moment of inertia.

Note For Problems 9.6-1 through 9.6-5, use the lower-bound moment of inertia for deflection of the composite section. Compute this as illustrated in Example 9.7. 9.6-3 For the beam of Problem 9.3-1, a. Compute the deflections that occur before and after the concrete has cured. b. If the live-load deflection exceeds L360 , select another steel shape using either LRFD or ASD.

Compute the nominal shear strength of an M1211.8 of A572 Grade 65 steel.

Estimate the transverse tensile strength of the concrete in Problem 12.6.

If the beam in Problem 5.5-9 i5 braced at A, B, and C, compute for the unbr Cb aced length AC (same as Cb for unbraced length CB). Do not include the beam weight in the loading. a. Use the unfactored service loads. b. Use factored loads.

A plate girder must be designed for the conditions shown in Figure P10.7-4. The given loads are factored, and the uniformly distributed load includes a conservative estimate of the girder weight. Lateral support is provided at the ands and at the load points. Use LRFD for that following: a. Select the, flange and web dimensions so that intermediate stiffeners will he required. Use Fy=50 ksi and a total depth of 50 inches. Bearing stiffeners will be used at the ends and at the load points, but do not proportion them. b. Determine the locations of the intermediate stiffeners, but do not proportion them.

Compute the nominal shear strength of an M107.5 of A572 Grad 65 steel.