PRESCRIPTIVE METHOD FOR RESIDENTIAL COLD-FORMED
STEEL FRAMING
Second Edition
Prepared for
The U.S. Department of Housing
and Urban Development
Office of Policy Development and Research
Washington, DC
Co-Sponsored by
The American Iron and Steel Institute
Washington, DC
and
The National Association of Home Builders
Washington, DC
by
NAHB Research Center, Inc. 400 Prince George's Boulevard Upper Marlboro, MD 20774-8731
August 1997
5.0
5.0 STEEL FLOOR FRAMING
5.1 Floor Construction
Cold-formed steel framing members shall comply with the provisions of Section 2.0. Steel floors shall be constructed in accordance with this section and Figure 5.1. 5.1.1 Applicability Limits
The applicability limits of Section 1.3 and Table 1.1 shall apply. 5.1.2 In-Line Framing.
Load bearing steel floor framing, wall framing, and ceiling/roof framing shall be constructed in-line with the vertical load bearing members (i.e. studs) located below. A maximum tolerance of 3/4 inch (19 mm) between the centerlines of the in-line members shall be permitted in accordance with Figure 1.2.
CONTENTS
STEEL FLOOR FRAMING . ............................................................................................. 21 5.1 Floor Construction . ............................................................................................... 21 5.2 Floor to Foundation or Bearing Wall Connection ................................................ 21 5.3 Allowable Joist Spans .......................................................................................... 21 5.4 Joist Bracing . ........................................................................................................ 21 5.5 Floor Cantilevers .................................................................................................. 22 5.6 Splicing................................................................................................................. 22 5.7 Framing of Floor Openings .................................................................................. 22 5.8 Floor Trusses ........................................................................................................ 22
5.2 Floor to Foundation or Bearing Wall Connection
Cold-formed steel floor framing shall be anchored to foundations, wood sills, or load bearing walls in accordance with Table 5.1 and Figures 5.1 through 5.10. Fastening of steel joists to other framing members shall be in accordance with Table 5.2.
5.3 Allowable Joist Spans
The clear span of cold-formed steel floor joists shall not exceed the limits set forth in Table 5.3 for single spans and Table 5.4 for multiple spans. When continuous joist members are used for multiple spans, the interior bearing supports shall be located within two feet (0.6 m) of mid-span of the steel joists, and the individual spans shall not exceed the applicable spans in the table. Floor joists shall have a bearing support length of not less than 1.5 inches (38 mm) for exterior wall supports and 3.5 inches (89 mm) for interior wall supports. Bearing stiffeners shall be installed at each joist bearing location in accordance with Section 2.9. The thickness of joist tracks shall be a minimum of 33 mils (0.84 mm) thick except when used as part of floor header or trimmer in accordance with Section 5.7. 5.4 Joist Bracing
The top flanges of floor joists shall be laterally braced by the application of floor fastened to the joists in accordance with Table 5.2. Floor joists with spans that exceed 12 feet (3.7 m) shall have the bottom flanges laterally braced in accordance with one of the following:
1. Gypsum board installed with minimum#6 screws in accordance with
the applicable building code, or
2. Continuous steel strapping installed in accordance with Figure 5.1 and 5.2.
Steel straps shall be at least 1-1/2 inches (38 mm) in width and 33 mils (0.84 mm) in thickness. Straps shall be fastened to the bottom flange of each joist with at least one #8 screw and shall be fastened to blocking with at least two #8 screws. Blocking or bridging (X-bracing) shall be installed between joists at a maximum spacing of 12 feet (3.7m) measured along the continuous strapping (perpendicular to the joist run). Blocking or bridging shall also be located at the termination of all straps.
5.5 Floor Cantilevers
Floor cantilevers for the second floor of a two-story building or the first floor of a one-story building shall not exceed 24 inches (610 mm) as illustrated in Figure 5.1. Cantilevers shall support interior floor loading only. Cantilevers, not exceeding 24 inches (610 mm) and supporting one floor and roof (first floor of a two story building), shall be permitted provided that all cantilevered joists are doubled (nested or back-to-back). The doubled cantilevered joists shall extend a minimum of 6 feet (1.8 m) toward the inside and shall be fastened with a minimum of two #8 screws spaced at 24 inches (610 mm) on center through the webs (for back-to-back) or flanges (for nested joists). Approved design is required for cantilevered areas supporting uniform live loads greater than 40 psf (1.92 kN/m2).
5.6 Splicing
Joists and other structural members shall not be spliced without an approved design. Splicing of tracks shall conform with Figure 5.11. 5.7 Framing of Floor Openings
Openings in floors shall be framed with header and trimmer joists. Header joist spans shall not exceed 8 feet (2.4 m) in length. Header and trimmer joists shall be fabricated from joist and track sections, which shall be of a minimum size and thickness as the adjacent floor joists and shall be installed in accordance with Figures 5.1, 5.12, and 5.13. Each header joist shall be connected to trimmer joists with a minimum of four 2 inch x 2 inch (51 mm x 51 mm) clip angles. Each clip angle shall be fastened to both the header and trimmer joists with four #8 screws evenly spaced on each leg of the clip angle. The clip angles shall have a thickness not less than that of the floor joist.
5.8 Floor Trusses
Cold-formed steel floor trusses shall be designed, braced, and installed in accordance with an approved design. Truss members shall not be notched, cut, or altered in any manner unless by an approved design. All trusses shall be aligned with load carrying members (i.e. studs) in the wall. Refer to AISI publication RG-9518 [17] “Design Guide For Cold-Formed Steel Trusses” for additional guidance.
Table 5.1
For SI:
1
1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 mph = 1.61 km/hr, 1 foot = 0.3m.
Use the highest of the wind speed and exposure or the seismic requirements for a given site.
2
All screw sizes shown are minimum
Table 5.2
Floor Fastening Schedule1
For SI: 1 inch = 25.4 mm
1
All screw sizes shown are minimum.
Head styles shall be bugle-head, flat-head, or similar with a minimum head diameter of 0.29 inch (7 mm).
2
Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4
Single Span
33 ksi Steel
1234
For SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
Table provides the maximum clear span in feet and inches.
Bearing stiffeners shall be installed at all support points and concentrated loads. Deflection criteria: L/480 for live loads; L/240 for total loads. Floor dead load = 10 psf (0.479 kN/m2) For actual size refer to Table 2.1.
5
Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4,5,6
Multiple Spans 33 ksi Steel
12
For SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
Table provides the maximum clear span in feet and inches to either side of the interior support. Interior bearing supports for multiple span joists shall consist of structural (bearing) walls or Bearing stiffeners shall be installed at all support points and concentrated loads. Deflection criteria: L/480 for live loads; L/240 for total loads. Floor dead load = 10 psf (0.479 kN/m2)
Interior supports shall be located within two feet (610 mm) of mid span provided that each of the resulting spans does not exceed the appropriate maximum span shown in the table above. For actual size refer to Table 2.1.
beams.
3456
7
冷弯型钢框架结构设计方法
第二版
为美国住房发展政策开发部门和华盛顿研究中心所准备
由美国华盛顿钢铁研究所联合主办
国家建筑协会，华盛顿
NAHB 研究中心，乔治王子的大道400号Marlboro.MD 20774-8731
1997.8
目录
5.0 钢楼板结构„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.1 楼板结构„„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.2 楼板与基础或承重墙连接„„„„„„„„„„„„„„„„„„„„21 5.3安装托梁的允许间距„„„„„„„„„„„„„„„„„„„„„„21 5.4托梁支撑„„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.5 悬臂楼板„„„„„„„„„„„„„„„„„„„„„„„„„„„22 5.6 接合„„„„„„„„„„„„„„„„„„„„„„„„„„„„„22 5.7开洞楼板框架„„„„„„„„„„„„„„„„„„„„„„„„„22 5.8 楼板桁架„„„„„„„„„„„„„„„„„„„„„„„„„„„22
5.0钢楼板结构 5.1 建筑楼板
冷弯钢结构应该符合2.0部分提供的要求。钢楼板应该按图5.1的标准来修建。 5.1.1适用性极限
适用性极限应该参考第1.3部分和表1.1。 5.1.2 线性结构
承重的钢楼板和屋顶应建造时应和竖向荷载的大小紧密联系。轴线的最大的容许间距是3/4英寸（19mm ）在图1.2中是可以的。
5.2 楼板与基础或承重墙连接 钢托梁和其他框架的锚固参考表5.2。 5.3 允许的安装托梁间距
冷弯钢楼板托梁的净跨在单跨时不应超过表5.3所规定的极限跨度，多跨时不应超过表5.4所规定的极限跨度。当连续的托梁用到多跨时，跨中支座应该被固定
冷弯钢结构楼板和基础、木基石或者承重墙的锚固长度参考表5.1或者图5.1。
在2英尺内，并且其余个跨跨距不应超过表中所要求的长度。楼板托梁在外墙上的支撑长度至少为1.5英寸，在内墙上的支撑长度不应少于3.5英寸。根据第2.9部分，每个托梁必须安装受力钢筋。除了用在板头时根据第5.7结选取，托梁的最厚处至少应该是33米尔。
5.4 安装托梁支撑
根据表5.2，托梁的顶端应该被楼板的侧面支撑。根据下面的要求，楼板托梁当超过12英尺时应该有底面侧向的支撑。
1根据建筑条例石膏板和直径最小为#6的螺丝安装时，或者
2 连续的钢约束安装应根据图5.1和5.2。当托梁厚度为33米尔时钢约束的长度至少为1－1/2英寸。托梁的底部应该至少安装1个#8的螺丝，挡板必须安装2个#8的螺丝。固结并且最大跨度为12英尺时必须安装挡板。每个约束的端点处也必须安装挡板。
5.5 楼板悬臂
像图5.1表示的那样，两层楼的第二层或者单程楼的第一层的悬臂楼板不应超过24英寸。悬臂只支撑内楼板荷载。不超过24英寸并且支撑一层楼面或屋顶（两层楼的第一层）的悬臂，悬臂的托梁应该被容许加倍。跨度为24英寸的加倍的悬臂托梁必须向内深入至少6英尺并且用#8的螺丝加固。活载大于192 kN/m2时的悬臂是必须得到批准才能设计的。
5.6 接合
托梁和其他结构构件在没有设计容许时是不能接合的。轨道接合参照图5.11。
5.7楼板开口的框架托梁接头的长度不应超过8英尺。在安装时托梁的接头的最小尺寸和厚度应该遵循图5.1,5.2,5.13。每个托梁的顶部应该以不低于四个2英寸×2英寸的构件和托梁连接。每个构件应该和托梁的顶部连接时用四个#8的螺丝甚至在构件的每个角上。构件的厚度不应小于托梁的。
5.8 楼板桁架
冷弯钢楼板桁架必须按照有效的方案来进行设计和安装。在没有设计批准时，每个桁架处不应被刻痕、截断、或者替换。每个桁架应该与墙内承载荷载构件共同排列。参考ASIS 出版的“冷弯钢桁架设计指南”
表 5.1
基础或承重墙所地板的连接要求
注明 : 1 英寸 = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 mph = 1.61 km/hr, 1 foot = 0.3m. 1 2
表 5.2 楼板固定表
注明: 1英寸= 25.4 毫米 1 所有螺丝给出的均是最小限值
2 螺丝顶部的形状应该是 喇叭型, 扁平型, 或最小直径是0.29英寸(7 mm).
表中所给的尺寸都是根据最高的风速和递增影响下得出的 所有螺丝给出的均是最小限值
冷弯薄壁型钢的容许间距1,2,3,4
单一间距 33 ksi Steel
1 2 3 4 5
注明: 1英寸 = 25.4毫米, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
上表提供了最大的间距
钢筋要被安装在支撑节点和集中力作用处 挠度标准: L/480 对于活载; L/240对于总荷载. 楼面恒载 = 10 psf (0.479 kN/m2) 实际尺寸参考表 2.1.
冷弯薄壁型钢的容许间距1,2,3,4,5,6
多间距 33 ksi Steel
注明: 1英寸 = 25.4毫米, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m. 1 2
上表提供了最大的间距 和 内部支撑每边的尺寸 结构墙或梁. 应该包括多间距托梁的内部支座
3 钢筋要被安装在支撑节点和集中力作用处 4 挠度标准: L/480 对于活载; L/240对于总荷载. 5
楼面恒载= 10 psf (0.479 kN/m2) 超过上表所给最大尺寸
7 实际尺寸参考表 2.1.
6 内部支撑应该被确定在说提供的中间跨度610mm 之内, 并且每个跨度不应
PRESCRIPTIVE METHOD FOR RESIDENTIAL COLD-FORMED
STEEL FRAMING
Second Edition
Prepared for
The U.S. Department of Housing
and Urban Development
Office of Policy Development and Research
Washington, DC
Co-Sponsored by
The American Iron and Steel Institute
Washington, DC
and
The National Association of Home Builders
Washington, DC
by
NAHB Research Center, Inc. 400 Prince George's Boulevard Upper Marlboro, MD 20774-8731
August 1997
5.0
5.0 STEEL FLOOR FRAMING
5.1 Floor Construction
Cold-formed steel framing members shall comply with the provisions of Section 2.0. Steel floors shall be constructed in accordance with this section and Figure 5.1. 5.1.1 Applicability Limits
The applicability limits of Section 1.3 and Table 1.1 shall apply. 5.1.2 In-Line Framing.
Load bearing steel floor framing, wall framing, and ceiling/roof framing shall be constructed in-line with the vertical load bearing members (i.e. studs) located below. A maximum tolerance of 3/4 inch (19 mm) between the centerlines of the in-line members shall be permitted in accordance with Figure 1.2.
CONTENTS
STEEL FLOOR FRAMING . ............................................................................................. 21 5.1 Floor Construction . ............................................................................................... 21 5.2 Floor to Foundation or Bearing Wall Connection ................................................ 21 5.3 Allowable Joist Spans .......................................................................................... 21 5.4 Joist Bracing . ........................................................................................................ 21 5.5 Floor Cantilevers .................................................................................................. 22 5.6 Splicing................................................................................................................. 22 5.7 Framing of Floor Openings .................................................................................. 22 5.8 Floor Trusses ........................................................................................................ 22
5.2 Floor to Foundation or Bearing Wall Connection
Cold-formed steel floor framing shall be anchored to foundations, wood sills, or load bearing walls in accordance with Table 5.1 and Figures 5.1 through 5.10. Fastening of steel joists to other framing members shall be in accordance with Table 5.2.
5.3 Allowable Joist Spans
The clear span of cold-formed steel floor joists shall not exceed the limits set forth in Table 5.3 for single spans and Table 5.4 for multiple spans. When continuous joist members are used for multiple spans, the interior bearing supports shall be located within two feet (0.6 m) of mid-span of the steel joists, and the individual spans shall not exceed the applicable spans in the table. Floor joists shall have a bearing support length of not less than 1.5 inches (38 mm) for exterior wall supports and 3.5 inches (89 mm) for interior wall supports. Bearing stiffeners shall be installed at each joist bearing location in accordance with Section 2.9. The thickness of joist tracks shall be a minimum of 33 mils (0.84 mm) thick except when used as part of floor header or trimmer in accordance with Section 5.7. 5.4 Joist Bracing
The top flanges of floor joists shall be laterally braced by the application of floor fastened to the joists in accordance with Table 5.2. Floor joists with spans that exceed 12 feet (3.7 m) shall have the bottom flanges laterally braced in accordance with one of the following:
1. Gypsum board installed with minimum#6 screws in accordance with
the applicable building code, or
2. Continuous steel strapping installed in accordance with Figure 5.1 and 5.2.
Steel straps shall be at least 1-1/2 inches (38 mm) in width and 33 mils (0.84 mm) in thickness. Straps shall be fastened to the bottom flange of each joist with at least one #8 screw and shall be fastened to blocking with at least two #8 screws. Blocking or bridging (X-bracing) shall be installed between joists at a maximum spacing of 12 feet (3.7m) measured along the continuous strapping (perpendicular to the joist run). Blocking or bridging shall also be located at the termination of all straps.
5.5 Floor Cantilevers
Floor cantilevers for the second floor of a two-story building or the first floor of a one-story building shall not exceed 24 inches (610 mm) as illustrated in Figure 5.1. Cantilevers shall support interior floor loading only. Cantilevers, not exceeding 24 inches (610 mm) and supporting one floor and roof (first floor of a two story building), shall be permitted provided that all cantilevered joists are doubled (nested or back-to-back). The doubled cantilevered joists shall extend a minimum of 6 feet (1.8 m) toward the inside and shall be fastened with a minimum of two #8 screws spaced at 24 inches (610 mm) on center through the webs (for back-to-back) or flanges (for nested joists). Approved design is required for cantilevered areas supporting uniform live loads greater than 40 psf (1.92 kN/m2).
5.6 Splicing
Joists and other structural members shall not be spliced without an approved design. Splicing of tracks shall conform with Figure 5.11. 5.7 Framing of Floor Openings
Openings in floors shall be framed with header and trimmer joists. Header joist spans shall not exceed 8 feet (2.4 m) in length. Header and trimmer joists shall be fabricated from joist and track sections, which shall be of a minimum size and thickness as the adjacent floor joists and shall be installed in accordance with Figures 5.1, 5.12, and 5.13. Each header joist shall be connected to trimmer joists with a minimum of four 2 inch x 2 inch (51 mm x 51 mm) clip angles. Each clip angle shall be fastened to both the header and trimmer joists with four #8 screws evenly spaced on each leg of the clip angle. The clip angles shall have a thickness not less than that of the floor joist.
5.8 Floor Trusses
Cold-formed steel floor trusses shall be designed, braced, and installed in accordance with an approved design. Truss members shall not be notched, cut, or altered in any manner unless by an approved design. All trusses shall be aligned with load carrying members (i.e. studs) in the wall. Refer to AISI publication RG-9518 [17] “Design Guide For Cold-Formed Steel Trusses” for additional guidance.
Table 5.1
For SI:
1
1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 mph = 1.61 km/hr, 1 foot = 0.3m.
Use the highest of the wind speed and exposure or the seismic requirements for a given site.
2
All screw sizes shown are minimum
Table 5.2
Floor Fastening Schedule1
For SI: 1 inch = 25.4 mm
1
All screw sizes shown are minimum.
Head styles shall be bugle-head, flat-head, or similar with a minimum head diameter of 0.29 inch (7 mm).
2
Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4
Single Span
33 ksi Steel
1234
For SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
Table provides the maximum clear span in feet and inches.
Bearing stiffeners shall be installed at all support points and concentrated loads. Deflection criteria: L/480 for live loads; L/240 for total loads. Floor dead load = 10 psf (0.479 kN/m2) For actual size refer to Table 2.1.
5
Allowable Spans For Cold-Formed Steel Floor Joists1,2,3,4,5,6
Multiple Spans 33 ksi Steel
12
For SI: 1 inch = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
Table provides the maximum clear span in feet and inches to either side of the interior support. Interior bearing supports for multiple span joists shall consist of structural (bearing) walls or Bearing stiffeners shall be installed at all support points and concentrated loads. Deflection criteria: L/480 for live loads; L/240 for total loads. Floor dead load = 10 psf (0.479 kN/m2)
Interior supports shall be located within two feet (610 mm) of mid span provided that each of the resulting spans does not exceed the appropriate maximum span shown in the table above. For actual size refer to Table 2.1.
beams.
3456
7
冷弯型钢框架结构设计方法
第二版
为美国住房发展政策开发部门和华盛顿研究中心所准备
由美国华盛顿钢铁研究所联合主办
国家建筑协会，华盛顿
NAHB 研究中心，乔治王子的大道400号Marlboro.MD 20774-8731
1997.8
目录
5.0 钢楼板结构„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.1 楼板结构„„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.2 楼板与基础或承重墙连接„„„„„„„„„„„„„„„„„„„„21 5.3安装托梁的允许间距„„„„„„„„„„„„„„„„„„„„„„21 5.4托梁支撑„„„„„„„„„„„„„„„„„„„„„„„„„„„21 5.5 悬臂楼板„„„„„„„„„„„„„„„„„„„„„„„„„„„22 5.6 接合„„„„„„„„„„„„„„„„„„„„„„„„„„„„„22 5.7开洞楼板框架„„„„„„„„„„„„„„„„„„„„„„„„„22 5.8 楼板桁架„„„„„„„„„„„„„„„„„„„„„„„„„„„22
5.0钢楼板结构 5.1 建筑楼板
冷弯钢结构应该符合2.0部分提供的要求。钢楼板应该按图5.1的标准来修建。 5.1.1适用性极限
适用性极限应该参考第1.3部分和表1.1。 5.1.2 线性结构
承重的钢楼板和屋顶应建造时应和竖向荷载的大小紧密联系。轴线的最大的容许间距是3/4英寸（19mm ）在图1.2中是可以的。
5.2 楼板与基础或承重墙连接 钢托梁和其他框架的锚固参考表5.2。 5.3 允许的安装托梁间距
冷弯钢楼板托梁的净跨在单跨时不应超过表5.3所规定的极限跨度，多跨时不应超过表5.4所规定的极限跨度。当连续的托梁用到多跨时，跨中支座应该被固定
冷弯钢结构楼板和基础、木基石或者承重墙的锚固长度参考表5.1或者图5.1。
在2英尺内，并且其余个跨跨距不应超过表中所要求的长度。楼板托梁在外墙上的支撑长度至少为1.5英寸，在内墙上的支撑长度不应少于3.5英寸。根据第2.9部分，每个托梁必须安装受力钢筋。除了用在板头时根据第5.7结选取，托梁的最厚处至少应该是33米尔。
5.4 安装托梁支撑
根据表5.2，托梁的顶端应该被楼板的侧面支撑。根据下面的要求，楼板托梁当超过12英尺时应该有底面侧向的支撑。
1根据建筑条例石膏板和直径最小为#6的螺丝安装时，或者
2 连续的钢约束安装应根据图5.1和5.2。当托梁厚度为33米尔时钢约束的长度至少为1－1/2英寸。托梁的底部应该至少安装1个#8的螺丝，挡板必须安装2个#8的螺丝。固结并且最大跨度为12英尺时必须安装挡板。每个约束的端点处也必须安装挡板。
5.5 楼板悬臂
像图5.1表示的那样，两层楼的第二层或者单程楼的第一层的悬臂楼板不应超过24英寸。悬臂只支撑内楼板荷载。不超过24英寸并且支撑一层楼面或屋顶（两层楼的第一层）的悬臂，悬臂的托梁应该被容许加倍。跨度为24英寸的加倍的悬臂托梁必须向内深入至少6英尺并且用#8的螺丝加固。活载大于192 kN/m2时的悬臂是必须得到批准才能设计的。
5.6 接合
托梁和其他结构构件在没有设计容许时是不能接合的。轨道接合参照图5.11。
5.7楼板开口的框架托梁接头的长度不应超过8英尺。在安装时托梁的接头的最小尺寸和厚度应该遵循图5.1,5.2,5.13。每个托梁的顶部应该以不低于四个2英寸×2英寸的构件和托梁连接。每个构件应该和托梁的顶部连接时用四个#8的螺丝甚至在构件的每个角上。构件的厚度不应小于托梁的。
5.8 楼板桁架
冷弯钢楼板桁架必须按照有效的方案来进行设计和安装。在没有设计批准时，每个桁架处不应被刻痕、截断、或者替换。每个桁架应该与墙内承载荷载构件共同排列。参考ASIS 出版的“冷弯钢桁架设计指南”
表 5.1
基础或承重墙所地板的连接要求
注明 : 1 英寸 = 25.4 mm, 1 psf = 0.0479 kN/m2, 1 mph = 1.61 km/hr, 1 foot = 0.3m. 1 2
表 5.2 楼板固定表
注明: 1英寸= 25.4 毫米 1 所有螺丝给出的均是最小限值
2 螺丝顶部的形状应该是 喇叭型, 扁平型, 或最小直径是0.29英寸(7 mm).
表中所给的尺寸都是根据最高的风速和递增影响下得出的 所有螺丝给出的均是最小限值
冷弯薄壁型钢的容许间距1,2,3,4
单一间距 33 ksi Steel
1 2 3 4 5
注明: 1英寸 = 25.4毫米, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m.
上表提供了最大的间距
钢筋要被安装在支撑节点和集中力作用处 挠度标准: L/480 对于活载; L/240对于总荷载. 楼面恒载 = 10 psf (0.479 kN/m2) 实际尺寸参考表 2.1.
冷弯薄壁型钢的容许间距1,2,3,4,5,6
多间距 33 ksi Steel
注明: 1英寸 = 25.4毫米, 1 psf = 0.0479 kN/m2, 1 foot = 0.3m. 1 2
上表提供了最大的间距 和 内部支撑每边的尺寸 结构墙或梁. 应该包括多间距托梁的内部支座
3 钢筋要被安装在支撑节点和集中力作用处 4 挠度标准: L/480 对于活载; L/240对于总荷载. 5
楼面恒载= 10 psf (0.479 kN/m2) 超过上表所给最大尺寸
7 实际尺寸参考表 2.1.
6 内部支撑应该被确定在说提供的中间跨度610mm 之内, 并且每个跨度不应