Structural Elements
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# Structural Elements for Architects and Builders, 1st Edition

Jonathan Ochshorn

Errata for First Edition

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p.379 Glossary. Change "Point of infection" to "Point of inflection"!
p.237 Example 9.14, step 2: The last sentence of this step should read: "For this example, we will choose a weld size of w = 3/16 in." (and not 3/8 in. as written; the rest of the example is correctly based on a 3/16 in. weld size).
p.148 Example 8.4, step 5: In the 6th line of step 5, the "combined CFSx" value should be 39.86 instead of 32.19 in3.
p.50 Chapter 2 (Loads): The second line from the top should read "pounds per square foot" rather than "pounds per square inch." The abbreviated "psf" is correct.
p.249 Appendix 1, Table A-1.1: To the right of the image in the upper cell, the statement that "Rules 1 and 2 derive from the horizontal equilibrium..." should be changed to "Rules 1 and 2 derive from the vertical equilibrium..." Similarly, the subheading in the second cell from the top should read: "From vertical equilibrium" rather than "horizontal equilibrium." All the equations and derivations are correct.
p.184 Chapter 8, Example 8.10: Under Beam design, positive moment (T-beam design), Step 2, change "compute negative design moment..." to "compute positive design moment..."
p.168 Reinforced concrete beams: Equation 8.20 is incorrect; the bracketed fraction should be [d - Asfy/(2x0.85f'cb)] rather than having the variable d in the numerator of the fraction. The steps that follow this equation, however, are correct.
p.211 Example 9.4, step 6: the parenthetical concluding remark should read, "consisting of four 5/8-in.-diameter bolts" rather than "consisting of six 1/2-in. diameter bolts." The calculations are OK.
p.243 Example 9.15, In the "problem definition" and "problem solution, step 1," the value of 0.74 for required bar area, As-required, should have in2 units.
p.182-183 Example 8.10, slab design, negative moment step 6, refers to "Equation 8.36"; it should be "Equation 8.35"; beam design, negative moment step 3, refers to "Equation 8.34"; it should be "Equation 8.33."
p.182 Example 8.10, step 7 refers to "Note 4 for slabs." This should read, instead, "keyed note d for slabs in Table 8.9."
p.175 Chapter 8: Line 12 in first paragraph refers to "Note 3 in Table 8.9." This should read, instead, "keyed note c in Table 8.9."
p.189, 190, and 191 Example 8.11: Captions for the figures associated with this example refer to the wrong example number. Figures 8.52 - 8.57 should refer to Example 8.11 instead of 8.10. In Figure 8.57, there are only 4 spaces shown where the beam elevation is labeled "6 @ 12' = 72". The diagram should be corrected to show 6 spaces instead of 4.
p.230, 234, 236, and 237 Examples 9.11 through 9.14: Captions for the figures associated with these examples refer to the wrong example numbers. Figure 9.30 should refer to Example 9.11 instead of 9.10; Figure 9.34 should refer to Example 9.12 instead of 9.11; Figure 9.35 should refer to Example 9.13 instead of 9.12; and Figure 9.36 should refer to Example 9.14 instead of 9.13.
p.164 Example 8.7: in both step 7 and step 8, the moment of inertia, I, is written as 88.6 in4 instead of 119 in4. The calculations and answer that follow are correct.
p.74 Figure 4.1: the flange thickness of 0.515 in. is incorrectly labelled tw instead of tf.
p.282 Appendix 3, Table A-3.9, Part B: The value for Glued laminated softwood timber, Douglas Fir-Larch, Grade L1D (Identification No. 5) should be 1,040,000 rather than 104,000.
p.148 Chapter 8, Example 8.4: Step 4, the last sentence should read: "This can be rewritten as CFSreq = M/(850) = 25,566/(850) = 30.08 in3." That is, the term, M/F'b, is deleted.
p.146 Chapter 8, Example 8.3: Trial 2, step 5, should read: "...since actual Sx = 1185 in3 ≥ required Sx = 1126 in3, the section is OK for bending." In other words, the conclusion is correct, but the less-than symbol should be changed to a greater-or-equal-to symbol.
p.95 Chapter 6, Example 6.3: Step 4 contains the equation for net area, instead of gross area, although the actual calculation shown is correct. The step should read: Using Equation 6.6 (but solving for Ag), and referring to Figure 6.6, find the required gross area, Ag = An + (no. of holes)(dh × t) = 9.52 + 2(0.4375 × 1.5) = 10.83 in2.
p.94 Chapter 6, Example 6.2: The caption for Figure 6.5 refers to "Figure 6.3" instead of "Figure 6.2."
p.182 Chapter 8, Example 8.10: In "Problem Solution" for slab design (step 2 for both negative and positive moment), moment values cannot be used because the live load is greater than 3 times the dead load — see note 1, Table A-8.7 for details.
p.103 Chapter 6, Example 6.5: In "Problem Solution" step 3a, the number 5.45 in. is incorrectly split up between the 3rd and 4th lines of that paragraph (i.e, as 5.4 at the end of line 3 and as 5 in. at the start of line 4). Also, on the 6th line of that paragraph, the units of 4.27 in. should be written as the area, 4.27 in2.
p.375 References: The American Concrete Institute's Building Code Requirements for Structural Concrete should be designated as (ACI 318-08) rather than (ACI 818-08).
p.162 Chapter 8, Example 8.6 Design steel beam. Under Girder design, step 3, the web thickness, tw was inadvertently "split" into two lines; the correct equation for actual web area is: Aw = d x tw = 20.7 x 0.35 = 7.25 in2.
p.294 Appendix 4, Table A-4.3. The moment of inertia (Ix) for the W27 x 146 should be 5660 rather than 5630 in4.
p.111 Chapter 7, Example 7.1 Analyze wood column. Add the following clarification at the end of step 2, part c: "It was not necessary to include the load combination consisting only of dead plus roof/construction live load (D + Lr) since not only is the sum of these loads less than the combination of dead plus live load, but the duration of load factor (CD = 1.25) effectively makes the wood stronger for this combination."

In step 2, part d, change the variable wB (4th line from the bottom of the page) to B.

p.94 Chapter 6, Example 6.3 Design wood tension element. Add "consisting only of live and dead loads in normal proportions" to the first sentence after Problem Definition, so that it reads as follows: Find an appropriate 2 x cross section (Hem-Fir No. 2) to support a tensile load of 5 kips consisting only of live and dead loads in normal proportions.
p.345 Appendix 9, Table A-9.1. Values for T-E and E were taken from an older (1991) version of the NDS; the correct values are reproduced here (red font), with incorrect values shown with strike-through font:

 L (in.) D (in.) Dr (in.) T (in.) T-E (in.) E (in.) 3 0.250 0.173 2.0 1.8125 1.8438 0.1875 0.1562 3 0.375 0.265 2.0 1.7500 1.7813 0.2500 0.2187 3 0.500 0.371 2.0 1.6875 0.3125 3 0.625 0.471 2.0 1.6250 1.5938 0.3750 0.4062 4 0.250 0.173 2.5 2.3125 2.3438 0.1875 0.1562 4 0.375 0.265 2.5 2.2500 2.2813 0.2500 0.2187 4 0.500 0.371 2.5 2.1875 0.3125 4 0.625 0.471 2.5 2.1250 2.0938 0.3750 0.4062 5 0.250 0.173 3.0 2.8125 2.8438 0.1875 0.1562 5 0.375 0.265 3.0 2.7500 2.7813 0.2500 0.2187 5 0.500 0.371 3.0 2.6875 0.3125 5 0.625 0.471 3.0 3.6250 2.5938 0.3750 0.4062 6 0.250 0.173 3.5 3.3125 3.3438 0.1875 0.1562 6 0.375 0.265 3.5 3.2500 3.2813 0.2500 0.2187 6 0.500 0.371 3.5 3.1875 0.3125 6 0.625 0.471 3.5 3.1250 3.0938 0.3750 0.4062

p.348 Appendix 9, Table A-9.5. Because both values and formatting need adjustment, the correct table is reproduced here, with incorrect values shown with strike-through font, and new or corrected values shown in red font:

 Fastener Type with Lateral Load CM "Dowel-type," wet when made, dry in-service: Varies as follows: 1 fastener only 1.0 2 or more fasteners in single row parallel to grain 1.0 Multiple rows of fasteners parallel to grain, separate splice plate each row 1.0 Fastener with diameter < 1/2 in. 1/4 in. 0.70 Multiple rows of fasteners without separate splice plates 0.4 "Dowel-type," wet when used (in service) 0.70 Fastener Type with Withdrawal Load CM Nails, wet when made, dry in-service 0.25 Nails, dry when made, wet in-service 0.25 Nails, wet when made, wet in-service 0.25 1.00 Lag screws and wood screws, wet in-service 0.70

p.265-266 Appendix 3, Table A-3.1. Values for Southern Pine should be changed as follows: in Parts B and C "Beams and stringers" and "Posts and timbers," change the Select Structural value from 900 to 1000; change No. 1 from 550 to 900; and change No. 2 from 525 to 550.

p.271 Appendix 3, Table A-3.5. Values for Southern Pine should be changed as follows: in Part A "Dimension lumber," change the Select Structural value from 1700 to 1850; change No. 1 from 1075 to 1175; change No. 2 from 875 to 950; and change No. 3 from 500 to 550.
p.276 Appendix 3, Table A-3.6. The "Notes" at the bottom of page 276 should be placed after the last part of Table A-3.6, i.e., immediately after part H on page 277.
p.59 Chapter 2. Under "Problem solution" for Example 2.5 (Calculate seismic loads), step 2, part b should be changed as follows: "...the values of Ss and S1 found in part A..." should refer instead to part a (i.e., lower-case "a" rather than upper-case "A").
p.110 Chapter 7. In the derivation of radius of gyration for a rectangular section (lines 6 and 7), the variables d and h in the equation for moment of inertia should be reversed. Then, I = hd3/12 and r = (I/A)0.5 = (hd3/12dh)0.5. The answer shown, 0.289d, is correct.
p.181-2 Chapter 8, Example 8.10, Step 1: The value for the factored (design) load of 445 lb/ft should be set equal to 0.445 kips/ft rather than 0.455 kips/ft. The subsequent calculations are then adjusted as follows:
• Step 2: The moment value is Mu = 0.445(32)/12 = 0.33 ft-kips = 4.005 in-kips.
• Step 3: R ≥ 4.005/(0.9 x 12 x 22) = 0.0927.

No further changes are needed.

p.184 Chapter 8, Example 8.10, Beam design, positive moment (T-beam design), Step 5: In the 4th line from the bottom of the page, the parenthetical phrase (see Note 2 in Table A-8-9) should be changed to (see Note "b" in Table A-8.9).
p.251 Appendix 2, Table A-2.1, Value for "volumetric weight" of wood should be changed from 165 to 25-50.
p.343 Appendix 8, Table A-8.9, heading. The second column heading from the right should be labeled with the small greek letter, rho, i.e., ρ, rather than r.
p.153 Chapter 8. The sentence in the middle of the second paragraph beginning, "Equation 8.12 would then become..." should be changed to read as follows: "Equation 8.12 would then become Sreq = Mmax/(1.1 × 0.6 × Fy) = Mmax / (0.66Fy)."

p.332 Appendix 8, Table A-8.4. The plastic section modulus value, Zx, for the W21 × 62 should be changed from 1441 to 144.
p.126 Chapter 7, Example 7.7, step 1. In the indented equation for Pu, the term (100 - ρg) should be (1.00 - ρg). The calculated result in the text is correct.
p.102 Chapter 6, Example 6.5, step 2(a). The allowable tension stress, written as "36," should be changed to "58," so the last part of the equation reads: 100/(0.5 x 58) = 3.44 in 2. The calculated result in the text is correct.
p.297-8 Appendix 4, Table A-4.4. Change "e" to x (occurs 4 times, including in image).

p.299 Appendix 4, Table A-4.5(A). Change "e" to x (occurs 3 times, including once in image). Change other "e" in image to y = x.

p.300-1 Appendix 4, Table A-4.5(B). Change "e" to x (occurs 3 times, including once in image). Change other "e" in image to y. Add y column to table.

p.311 Appendix 6, Table A-6.1 Add note "1," keyed to table heading, as follows: Note: 1. The shear lag coefficient, U, for all tension members except plates and HSS, can be taken as U = 1 - x/l, where x is the distance measured from the connection plane to the centroid of the member and l is the length of the connection, measured either along the weld or measured from the first to the last bolt, in either case parallel to the direction of the tension force. For wide-flange shapes bolted through the flanges, the centroid is taken for half of the cross section, i.e., for the "tee"(WT shape), rather than for the whole W shape. Alternatively, the values for U listed in this table can be used in lieu of this equation.