QUESTION: (FALL2010) CSA Standard S6, Canadian Highway Bridge Design Code, requires that cross-frame connection plates be connected to the flanges of bridge girders. The bolted detail, as shown (in Figure 1), appears to be quite popular in rehabilitation work. I heard that this bolted detail qualifies for a “Category B“ fatigue detail, but it is not clear to me how simply bolting the stiffener to the bottom flange makes things better because the web weld is still present. ANSWER: Where the stiffener also serves as a cross-frame connection plate, both distortion-induced fatigue and load-induced fatigue should be considered. The bolted detail as shown does not alter the stiffener-to-web welded fatigue detail with respect to load-induced fatigue because this welded detail remains “Category C1”. However, connecting the connection plate to the flanges (when done correctly) should improve the distortion-induced fatigue resistance substantially. In order to avoid welded attachments in the tension flange, many older welded steel bridge girders feature cross-frame connection plates that were either cut short from, or ground to bear on, the tension flange. This outdated practice inadvertently resulted in the web taking out-of-plane stresses due to relative displacements of adjacent girders. These stress ranges, typically unaccounted for in the analyses, have been identified as the common cause of distortion-induced fatigue damage to welded bridge girders. Recent editions of CSA S6 require that cross-frames and diaphragms be connected to each flange for a minimum force of 90 kN.

[fusion_builder_container hundred_percent="no" equal_height_columns="no" hide_on_mobile="small-visibility,medium-visibility,large-visibility" background_position="center center" background_repeat="no-repeat" fade="no" background_parallax="none" enable_mobile="no" parallax_speed="0.3" video_aspect_ratio="16:9" video_loop="yes" video_mute="yes" overlay_opacity="0.5" border_style="solid" padding_top="20px" padding_bottom="20px"][fusion_builder_row][fusion_builder_column type="1_1" layout="1_1" spacing="" center_content="no" hover_type="none" link="" min_height="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" class="" id="" background_color="" background_image="" background_position="left top" background_repeat="no-repeat" border_size="0" border_color="" border_style="solid" border_position="all" padding="" dimension_margin="" animation_type="" animation_direction="left" animation_speed="0.3" animation_offset="" last="no"][fusion_text] QUESTION: (2015) For a knife-edge beam shear connection with double-angle welded to the support (Figure 2), can the top edge of the angles also be welded in order to increase the weld capacity? ANSWER: Beam shear connections must exhibit sufficient end rotation to allow the attainment of bending capacity of the simply supported beam, etc. Welding the top edge of the angles to the support inhibits end rotation and should therefore be avoided. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (FALL2015) I recently came across some fully threaded A325 bolts in the connections of a building structure. Are these bolts permitted? Do they have the same resistances versus bolts with regular thread length? How are they identified after installation? Do they offer any benefit? ANSWER: A325 bolts threaded full length are permitted under Supplementary Requirement S1 of ASTM A325. They are restricted to bolt lengths within the length of four times the nominal diameter. Bolt resistances: Since the tensile resistance is based on the threaded area (0.75Ab) it is not affected by the longer thread length. However, the bearing-type shear resistance must be reduced to account for threads intercepting the shear plane. When used in a slip-critical joint with a long grip, the smaller (threaded) bolt area in the entire grip affects the relationship between the clamping force and bolt elongation and may result in a reduction in clamping force when using the turn-of-nut installation method. The significance of this effect is a study in pursuit. Identification: The bolt head is marked with the symbol “A325T” instead of “A325” as shown in Figure 1. Benefits: They offer no benefit in terms of bolt resistance. However, the fabricator and erector may find their use viable for certain applications from the standpoint of ordering and inventory control, particularly for applications where thin connected steel parts, instead of the bolts, control the connection shear resistance. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (WINTER2014/2015) How is the shear resistance for gross section of gusset plates determined – should I use Clause 13.4.3 of S16-09 on webs of flexural members not having two flanges or Clause 13.11 on block shear? They give very different results. ANSWER: Neither. Clause 21.12, “Connected elements under combined tension and shear stresses”, a new clause introduced in CSA S16-14, covers this. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SUMMER2014) Are bolted moment connections used in a canopy structure required to be slip critical? My question relates to a situation where slip critical connections are not required for deflection control. I have many years of connection design experience but seldom had to provide slip-critical connections for wind-load resisting braced bents or moment frames. ANSWER: The key question here is whether fatigue is a consideration; will the structure be subjected to repetitive loading and stress reversal? A relatively light canopy type of structure subjected to gusty local wind load may experience stress reversal and a significant number of load cycles to warrant such assessment. The judgement rests with the engineer responsible for the design of the structure. Fatigue design is covered in Clause 26 of S16. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: I find the design requirements for pin-connected tension members as stipulated in CSA S16-09 very difficult to satisfy. They appear to mandate the use of eyebars. Have I missed something? ANSWER: The requirements in CSA S16-09 aim to ensure a gross-section yielding ultimate limit state and are therefore quite restrictive. New requirements have been introduced in CSA S16-14. This new provision improves design versatility considerably. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2014) When only one leg of an angle tension member is attached to its end supports, with longitudinal fillet welds, how do I determine if shear lag is important and how is it accounted for? ANSWER: The effect due to shear lag in a tension member is usually accounted for by means of an effective area method. For weld-connected members, Clause 12.3.3.3 of CSA S16-09 applies to members of various cross sections in general. The cross-section area of the angle is divided into two components, i.e., the attached leg and the outstanding leg. Figure 1(a) shows an angle connected by a pair of longitudinal welds of length, L . For the attached leg, shear lag is a factor when L ≤ 2 w 2 . In accordance with Clause 12.3.3.3 (b)(ii) and (iii), its effective net area, A n2 , as shown in Figure 1(b), is determined based on the weld configuration and, for short welds, also the leg thickness. The effective net area of the outstanding leg, A n3 , is calculated according to Clause 12.3.3.3(c). Its shear lag effect is given as a function of the ratio of the eccentricity of the weld with respect to the centroid of the outstanding leg, x , to the weld length, L . Then the tensile resistance of the member is calculated in accordance with Clause 13.2(a)(iii) using the total effective net area of the angle section, A ne = A n2 + A n3 . Further information may be found in the CISC Commentary on CSA S16-09 in Part 2 of the Handbook of Steel Construction. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2013) Clause 13.11 of S16-09 appears to have omitted the check for shear rupture of net section. What has happened to the shear rupture failure mode and where is the provision for pure shear rupture? ANSWER: The equation provided in Clause 13.11 of S16-09, as shown below, consists of both the tension and shear contributions to the block shear resistance of a bolted joint. The first term accounts for the resistance against tension whereas the second term represents the shear component. An example is shown in Figure 2a. The ultimate resistance of block shear is attained when the net section(s) subjected to tension reaches its fracture capacity. Typically, the deformation associated with this tensile capacity is too small to mobilize complete shear rupture at the same time. As recommended by Driver et al, the shear component is based on 0.6 times the mean value of F y and F u in this calculation. It should be noted that the gross area in shear, A gv (taken as the area of the plane(s) tangential to the bolt holes), is used in this calculation.Pure shear rupture, as shown for the example in Figure 2b, should also be considered. The second term of the equation above covers it. In the absence of the above-mentioned deformation incompatibility, larger shear resistance can be attained for pure shear rupture. However, Clause 13.11 provides a simple solution. Figure 2a: Block Shear Figure 2b: Shear Rupture [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2013) How is the strength reduction factor for multi-orientation fillet welds, Mw, applied? Please show an example. ANSWER: In the weld configuration shown in Figure 1, 8-millimetre fillet welds are used, X u = 490 MPa and the plate is G40.21 350W steel. Note that the farside plate is thicker. In accordance with CSA S16-09 Clause 13.13.2.2: V r = 0.67 ɸ w A w X u (1.00 + 0.50 sin 1.5 θ) M w where:θ = angle of axis of weld segment with respect to the line of action of the applied force M w = strength reduction factor for multi-orientation fillet welds a) Weld segment at θ = 60 o : Orientation of the weld segment under consideration: θ 1 = 60 o Orientation of the weld segment in the joint that is nearest to 90 o : θ 2 = θ 1 = 60 o b) Longitudinal weld segments (θ= 0 o ): Orientation of the weld segment under consideration: θ 1 = 0 o Orientation of the weld segment in the joint that is nearest to 90 o : θ 2 = 60 o c) Weld group resistance: V r = 2 x 0.67 x 0.67 x 8 x 100 x 0.707 x 0.490 (1.00 + 0.50 sin 1.5 0 o ) 0.895 + 0.67 x 0.67 x 8 x 120 x 0.707 x 0.490 (1.00 + 0.50 sin 1.5 60 o ) 1.00 = 2 x 111 + 209 = 431 kNFor matching electrodes, the base metal resistance need not be checked Figure 1: Strength Reduction for Multi-Orientation Fillet Welds [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (FALL2012) When designing bolted connections, are seismic loads considered to be static or cyclic? ANSWER: The Seismic Corner article entitled “Bolted Connections for Seismic Applications” in CISC publication, Advantage Steel No. 31 (Summer 2008), outlined the requirements for bolted connections for seismic applications in accordance with S16-01. The article is available at: https://cisc-icca.ca/ciscwp/product/advantage-steel-no-31/ In NBC 2010 and S16-09, the building height restriction for Conventional Construction where the specified short-period spectral acceleration, IEFaSa(0.2), exceeds 0.35 has been increased. The above mentioned requirements for bolted connections also apply to these taller structures of Conventional Construction. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (FALL2012) When designing fillet welds in shear, is it necessary to check the base metal resistance at the fusion face? ANSWER: In accordance with S16-01, the shear resistance of fillet welds is taken as the lesser of: (a) the weld metal resistance given as a function of the ultimate strength of the electrode, Xu , and the effective throat area, Aw and (b) the base metal resistance given as a function of its tensile strength, Fu , and the fusion face area, Am. Unless over-matched electrodes are used the base metal resistance does not govern the design of longitudinally loaded joints. However, when the weld orientation approaches the transversely loaded case the base metal resistance governs due to the significantly larger weld metal resistance.In S16-09, it is no longer necessary to check the base metal strength at the fusion face when matching electrodes are used (Clause 13.13.2.2). Research studies conducted at the University of Alberta have demonstrated that the base metal resistance determined using the virgin strength of the base metal does not represent the shear resistance. The researchers pointed to the fact that the properties of the base metal at the fusion face are influenced by intermixing of the weld and base metals. Unless over-matched electrodes are used, base metal resistance at the fusion face need not be checked, regardless of weld orientation.For a list of matching electrodes for CSA G40.21 steels, see Table 4 in S16-09. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2012) When wide-flange purlins are also subjected to significant axial tension, which is transmitted by connecting the bottom flange to the supports with two transverse lines of high strength bolts, how do I account for shear lag? Specifically, should the effective net area, A ne , be taken as 0.75A n , as provided in Clause 12.3.3.2 (c) (ii) of S16-09? ANSWER: The approach as you described is unconservative. In this situation, the effect of shear lag is more severe than the case for angles connected by one leg with two transverse lines of fasteners. Hence A ne < 0.60A n . On the other hand, the lower bound for A ne may be taken as A nf , where A nf is the net area of the connected flange alone. Therefore, A ne should lie somewhere between A nf and 0.60A n . [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2011) Is knife edge angle connection the right choice for axial tension or combined shear and axial tension? ANSWER: Knife edge angle connection, commonly known as knife connection, is a very common type of beam shear connection. It features a pair of angles that are typically welded to the column in the shop and bolted to the beam web in the field (Figure 1). While knife connection serves as a popular beam shear connection, its use is not recommended where significant axial tensile forces are to be transmitted, such as end connections for braced frame members and collectors that are subjected to significant axial tensile forces. Research studies, reported in the reference below, have demonstrated that knife connection exhibits limited axial tensile resistance. In the reference below, the test results of several other common beam shear connections subjected to combined shear and axial forces were also reported. Reference: Guravich, S. J. and Dawe, J. L. 2006. Simple beam connections in combined shear and tension. Canadian Journal of Civil Engineering. 33(4): 357-372. Figure 1: Knife Edge Connection [/fusion_text][/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

[fusion_builder_container hundred_percent="no" equal_height_columns="no" hide_on_mobile="small-visibility,medium-visibility,large-visibility" background_position="center center" background_repeat="no-repeat" fade="no" background_parallax="none" enable_mobile="no" parallax_speed="0.3" video_aspect_ratio="16:9" video_loop="yes" video_mute="yes" overlay_opacity="0.5" border_style="solid" padding_top="20px" padding_bottom="20px"][fusion_builder_row][fusion_builder_column type="1_1" layout="1_1" spacing="" center_content="no" hover_type="none" link="" min_height="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" class="" id="" background_color="" background_image="" background_position="left top" background_repeat="no-repeat" border_size="0" border_color="" border_style="solid" border_position="all" padding="" dimension_margin="" animation_type="" animation_direction="left" animation_speed="0.3" animation_offset="" last="no"][fusion_text] QUESTION: (2015) Clause 13.13.2.2 of S16-14 waives the base metal capacity requirement for fillet welds except where over-matched electrodes are used. This suggests that the rated strength of the over-matched electrode should be used to calculate the weld resistance but W59-13 requires that matching electrode strength to be used in this situation. What should I do? ANSWER: Until these standards reconcile, they can be satisfied if the matching electrode strength (smaller) is used in this situation. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SPRING2013) How is the strength reduction factor for multi-orientation fillet welds, Mw, applied? Please show an example. ANSWER: In the weld configuration shown in Figure 1, 8-millimetre fillet welds are used, X u = 490 MPa and the plate is G40.21 350W steel. Note that the farside plate is thicker. In accordance with CSA S16-09 Clause 13.13.2.2: V r = 0.67 ɸ w A w X u (1.00 + 0.50 sin 1.5 θ) M w where:θ = angle of axis of weld segment with respect to the line of action of the applied force M w = strength reduction factor for multi-orientation fillet welds a) Weld segment at θ = 60 o : Orientation of the weld segment under consideration: θ 1 = 60 o Orientation of the weld segment in the joint that is nearest to 90 o : θ 2 = θ 1 = 60 o b) Longitudinal weld segments (θ= 0 o ): Orientation of the weld segment under consideration: θ 1 = 0 o Orientation of the weld segment in the joint that is nearest to 90 o : θ 2 = 60 o c) Weld group resistance: V r = 2 x 0.67 x 0.67 x 8 x 100 x 0.707 x 0.490 (1.00 + 0.50 sin 1.5 0 o ) 0.895 + 0.67 x 0.67 x 8 x 120 x 0.707 x 0.490 (1.00 + 0.50 sin 1.5 60 o ) 1.00 = 2 x 111 + 209 = 431 kNFor matching electrodes, the base metal resistance need not be checked Figure 1: Strength Reduction for Multi-Orientation Fillet Welds [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (FALL2012) When designing fillet welds in shear, is it necessary to check the base metal resistance at the fusion face? ANSWER: In accordance with S16-01, the shear resistance of fillet welds is taken as the lesser of: (a) the weld metal resistance given as a function of the ultimate strength of the electrode, Xu , and the effective throat area, Aw and (b) the base metal resistance given as a function of its tensile strength, Fu , and the fusion face area, Am. Unless over-matched electrodes are used the base metal resistance does not govern the design of longitudinally loaded joints. However, when the weld orientation approaches the transversely loaded case the base metal resistance governs due to the significantly larger weld metal resistance. In S16-09, it is no longer necessary to check the base metal strength at the fusion face when matching electrodes are used (Clause 13.13.2.2). Research studies conducted at the University of Alberta have demonstrated that the base metal resistance determined using the virgin strength of the base metal does not represent the shear resistance. The researchers pointed to the fact that the properties of the base metal at the fusion face are influenced by intermixing of the weld and base metals. Unless over-matched electrodes are used, base metal resistance at the fusion face need not be checked, regardless of weld orientation.For a list of matching electrodes for CSA G40.21 steels, see Table 4 in S16-09. [/fusion_text][/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

[fusion_builder_container hundred_percent="no" equal_height_columns="no" hide_on_mobile="small-visibility,medium-visibility,large-visibility" background_position="center center" background_repeat="no-repeat" fade="no" background_parallax="none" enable_mobile="no" parallax_speed="0.3" video_aspect_ratio="16:9" video_loop="yes" video_mute="yes" overlay_opacity="0.5" border_style="solid" padding_top="20px" padding_bottom="20px"][fusion_builder_row][fusion_builder_column type="1_1" layout="1_1" spacing="" center_content="no" hover_type="none" link="" min_height="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" class="" id="" background_color="" background_image="" background_position="left top" background_repeat="no-repeat" border_size="0" border_color="" border_style="solid" border_position="all" padding="" dimension_margin="" animation_type="" animation_direction="left" animation_speed="0.3" animation_offset="" last="no"][fusion_text] QUESTION: (SUMMER2016) In National Building Code of Canada 2015, the period dependant Site Coefficient F(T), used for determination of seismic Design Spectral Accelerations, has replaced Site Coefficients Fa and Fv. CSA Standard S16-14, however, continues to reference Site Coefficients, Fa and Fv. Is S16-14 out of step with NBC 2015? ANSWER: CSA S16-14 is compatible with NBC 2015. In S16-14, coefficients F a and F v , appear in two expressions: the short-period specified spectral acceleration ratio, I E F a S a (0.2), and the one-second specified spectral acceleration ratio, I E F v S a (1.0). Certain values of these quantities serve as triggers for more stringent requirements whereas other values set the conditions for relaxation. Although F(T) has replaced F a and F v for the purpose of determination of Design Spectral Accelerations in NBC 2015 the Code retains the expressions I E F a S a (0.2) and I E F v S a (1.0) as triggers. As defined in Sentence 4.1.8.4. (7) of NBC 2015, F a = F(0.2) and F v = F(1.0). Ideally, F(0.2) and F(1.0) should also replace F a and F v respectively in these trigger expressions. This was not possible in the 2015 code cycle for the following reason: In order to be considered for adoption by NBC 2015, CSA material design standards, S16, A23.3 etc., must be published in 2014. However, changes proposed for NBC, including the period dependant Site Coefficient F(T), could not be finalized in time to meet the publication schedule for the CSA standards. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SUMMER2013) Is there a standard for anchor bolts? ANSWER: Yes, ASTM F1554 covers three grades of anchor bolts: Grade 36 (248 MPa), Grade 55 (380 MPa) and Grade 105 (724 MPa). The vast majority of anchor bolts (or anchor rods as defined in CSA S16-09) are used to position, level and secure base plates for concentrically loaded gravity columns. Fabricators have traditionally supplied these anchor rods manufactured from round bar stocks produced to ASTM A36 (or CSA G40.21 300W). Since the introduction of ASTM F1554, Grade 36 products fill this role. Grades 55 and 105 are produced to meet higher specified strengths. In addition, when specified in the purchased order as a ‘supplementary requirement,’ they are supplied to meet specific Charpy notch-toughness with test values. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (SUMMER2013) What are the most common high-strength bolt products used in building construction? ANSWER: Three-quarter-inch A325 bolts are still very common. Some fabricators/erectors prefer seven-eighth-inch A325 bolts, especially for large projects. A490 bolts are used increasingly in building construction. Typically, they are selected for connections resisting very large forces while A325 bolts may be used elsewhere in the structure. In such applications, care must be taken to prevent A325 bolts from being inadvertently installed in holes designed to receive A490 bolts. It is prudent to segregate them by size, typically, a quarter of an inch difference in diameter. Practical combinations include: a) 1˝ A490 bolts for heavy connections and ¾˝ A325 bolts elsewhere; and b) 1⅛˝ A490 bolts for heavy connections and ⅞˝ A325 bolts elsewhere. Where pre-tensioned installation is required, twist-off type tension-control bolts (assemblies) have emerged to be viable options. ASTM F1852 and ASTM F2280 bolts (twist-off type) share the ultimate-limit-state resistances with A325 bolts and A490 bolts respectively. However, CSA S16-09 specifies smaller values for 5 per cent slip coefficients, c1, for these twist-off type bolt assemblies versus those of high strength bolts pre-tensioned to meet the turn-of-nut method of installation. For further discussion on ASTM F1852 and ASTM F2280, visit Q & A Column in Advantage Steel No. 38. A490 and F2280 products shall not be galvanized. Use of metric bolts is still rare because they are unavailable unless a special order for a very large quantity is placed with advance notice. [/fusion_text][fusion_separator style_type="single solid" hide_on_mobile="small-visibility,medium-visibility,large-visibility" top_margin="10px" bottom_margin="10px" border_size="2" alignment="center" /][fusion_text] QUESTION: (FALL2010) CISC/CPMA Standard 1-73a versus CISC/CPMA Standard 2-75: What do they have in common and what are the major differences? ANSWER: These standards provide essentially the same laboratory requirements. The provision for surface preparation reflects the key difference. In addition to removal of grease and oil in accordance with SSPC Standard SP1, CISC/CPMA 2-75 requires steel cleaning in accordance with SSPC SP7, Brush-Off Blast Cleaning. Where CISC/CPMA 2-75 serves as a primer, it should be compatible with the top coat. CISC/CPMA 1-73a is a standard for one-coat paint, not a standard for primer. [/fusion_text][/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]

FAQs Archive – CISC-ICCA

Bridge Structures

QUESTION: (FALL2010) CSA Standard S6, Canadian Highway Bridge Design Code, requires that cross-frame connection plates be connected to the flanges of bridge girders. The bolted detail, as shown (in Figure 1), appears to be quite popular in rehabilitation work. I heard that this bolted detail qualifies for a “Category B“ fatigue detail, but it is not [...]

CISCWebAdmin2017-10-03T15:17:18-04:00October 3rd, 2017|

Building Structures – General

QUESTION: (SPRING2012) When CSA G40.21 300W steel strip is specified as the material for light braces in a building structure, can commercial grade steel products be used instead? What if they are supplied with a test report showing yield stress values matching or exceeding 300 MPa? ANSWER: No. The reasons include: a) Commercial grade steel [...]

CISCWebAdmin2017-10-03T15:20:29-04:00October 3rd, 2017|

Connections – Bolts & Bolting

QUESTION: (FALL2015) I recently came across some fully threaded A325 bolts in the connections of a building structure. Are these bolts permitted? Do they have the same resistances versus bolts with regular thread length? How are they identified after installation? Do they offer any benefit? ANSWER: A325 bolts threaded full length are permitted under Supplementary [...]

CISCWebAdmin2017-10-03T15:27:53-04:00October 3rd, 2017|

– Column Bases & Anchor Rods

QUESTION: (SUMMER2014) I am involved with evaluation of an existing building structure for compliance with the current code. The structure is in a sound condition. It satisfies the building code and CSA S16-09 for the intended occupancy except that the column bases have 2 anchor rods instead of 4. In one area, a row of [...]

CISCWebAdmin2017-10-03T15:23:57-04:00October 3rd, 2017|

– General

QUESTION: (2015) For a knife-edge beam shear connection with double-angle welded to the support (Figure 2), can the top edge of the angles also be welded in order to increase the weld capacity? ANSWER: Beam shear connections must exhibit sufficient end rotation to allow the attainment of bending capacity of the simply supported beam, etc. [...]

CISCWebAdmin2017-10-03T15:28:52-04:00October 3rd, 2017|

– Welds & Welding

QUESTION: (2015) Clause 13.13.2.2 of S16-14 waives the base metal capacity requirement for fillet welds except where over-matched electrodes are used. This suggests that the rated strength of the over-matched electrode should be used to calculate the weld resistance but W59-13 requires that matching electrode strength to be used in this situation. What should I [...]

CISCWebAdmin2017-10-03T15:24:45-04:00October 3rd, 2017|

Fabrication & Erection

QUESTION: (SUMMER2014) I am involved with evaluation of an existing building structure for compliance with the current code. The structure is in a sound condition. It satisfies the building code and CSA S16-09 for the intended occupancy except that the column bases have 2 anchor rods instead of 4. In one area, a row of [...]

CISCWebAdmin2017-10-03T16:34:18-04:00October 3rd, 2017|

General – Brittle Fracture

QUESTION: (FALL2015) I am involved with the design of an unenclosed industrial structure for which neither the building code nor the bridge code applies. Should I specify notch-tough steel? Are notch-tough W-shapes available? How do I determine the appropriate level of notch-toughness? ANSWER: Brittle fracture is a complex subject. In order to limit the probability [...]

CISCWebAdmin2017-10-03T16:39:37-04:00October 2nd, 2017|

– Coatings & Corrosion Protection

QUESTION: (FALL2010) CISC/CPMA Standard 1-73a versus CISC/CPMA Standard 2-75: What do they have in common and what are the major differences? ANSWER: These standards provide essentially the same laboratory requirements. The provision for surface preparation reflects the key difference. In addition to removal of grease and oil in accordance with SSPC Standard SP1, CISC/CPMA 2-75 [...]

CISCWebAdmin2017-10-03T15:32:54-04:00October 2nd, 2017|

– Codes & Standards

QUESTION: (SUMMER2016) In National Building Code of Canada 2015, the period dependant Site Coefficient F(T), used for determination of seismic Design Spectral Accelerations, has replaced Site Coefficients Fa and Fv. CSA Standard S16-14, however, continues to reference Site Coefficients, Fa and Fv. Is S16-14 out of step with NBC 2015? ANSWER: CSA S16-14 is compatible [...]

CISCWebAdmin2017-10-03T16:38:09-04:00October 2nd, 2017|