><B ><FONT face="Times New Roman">“321” </FONT></B><B >钢桥设计基本参数</B><BR><BR><FONT face="Times New Roman"> </FONT>简介：装配式公路钢桥（简称<FONT face="Times New Roman">“<st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="321" UnitName="”">321”</st1:chmetcnv></FONT>钢桥）是在原英制贝雷桁架桥的基础上，结合我国国情和实际情况研制而成的快速组装桥梁<FONT face="Times New Roman">,</FONT>材料为<FONT face="Times New Roman">16Mn</FONT>。<BR><BR><FONT face="Times New Roman">“<st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="321" UnitName="”">321”</st1:chmetcnv></FONT>钢桥属临时性桥梁结构，钢材的容许应力按基本容许应力提高<FONT face="Times New Roman">30%</FONT>，本桥设计时采用的容许应力按下列确定：<BR><FONT face="Times New Roman"> 16</FONT>锰钢的拉应力、压应力及弯应力：<BR><FONT face="Times New Roman"> 1.3×210=273 MPa<BR> 16</FONT>锰钢的剪应力：<BR><FONT face="Times New Roman"> 1.3×120=156 MPa<BR> </FONT>销子为<FONT face="Times New Roman">30</FONT>铬锰钛，插销为弹簧钢<BR><FONT face="Times New Roman"> 30</FONT>铬锰钛的拉应力、压应力及弯应力<BR><FONT face="Times New Roman"> 0.85×1300=1105 MPa<BR>30</FONT>铬锰钛的剪应力<BR><FONT face="Times New Roman"> 0.45×1300=585 MPa <BR> <BR>2</FONT>、钢梁截面特性<BR>（<FONT face="Times New Roman">1</FONT>）、桁架上下弦杆系由各两根<FONT face="Times New Roman">10</FONT>号热轧槽钢背靠背组合而成，腹杆由<FONT face="Times New Roman">8</FONT>号工字钢组成；<BR>（<FONT face="Times New Roman">2</FONT>）、<FONT face="Times New Roman">“<st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="321" UnitName="”">321”</st1:chmetcnv></FONT>钢桥在大多数情况下，最大跨径是由容许弯矩控制，但在个别情况下，是由剪力控制。<BR><BR>桥梁几何特性表<BR>（表中数值为半边桥之值，全桥时应乘<FONT face="Times New Roman">2</FONT>）<BR>几何特性<FONT face="Times New Roman"> W</FONT>（<FONT face="Times New Roman">cm3</FONT>）<FONT face="Times New Roman"> I</FONT>（<FONT face="Times New Roman">cm4</FONT>）<BR>结构构造<FONT face="Times New Roman"> <BR></FONT>单排单层<FONT face="Times New Roman"> </FONT>不加强<FONT face="Times New Roman"> 3578.5 250497.2<BR> </FONT>加强<FONT face="Times New Roman"> 7699.1 577434.4<BR></FONT>双排单层<FONT face="Times New Roman"> </FONT>不加强<FONT face="Times New Roman"> 7157.1 500994.4<BR> </FONT>加强<FONT face="Times New Roman"> 15398.3 1154868.8<BR></FONT>三排单层<FONT face="Times New Roman"> </FONT>不加强<FONT face="Times New Roman"> 10735.6 751491.6<BR> </FONT>加强<FONT face="Times New Roman"> 23097.4 1732303.2<BR></FONT>双排双层<FONT face="Times New Roman"> </FONT>不加强<FONT face="Times New Roman"> 14817.9 2148588.8<BR> </FONT>加强<FONT face="Times New Roman"> 30641.7 4596255.2<BR></FONT>三排双层<FONT face="Times New Roman"> </FONT>不加强<FONT face="Times New Roman"> 22226.8 3222883.2<BR> </FONT>加强<FONT face="Times New Roman"> 45962.6 6894382.8<BR></FONT>桁架容许内力表<BR>桥型<FONT face="Times New Roman"> </FONT>不加强桥梁<FONT face="Times New Roman"> </FONT>加强桥梁<BR>容许内力<FONT face="Times New Roman"> </FONT>单排单层<FONT face="Times New Roman"> </FONT>双排单层<FONT face="Times New Roman"> </FONT>三排单层<FONT face="Times New Roman"> </FONT>双排双层<FONT face="Times New Roman"> </FONT>三排双层<FONT face="Times New Roman"> </FONT>单排单层<FONT face="Times New Roman"> </FONT>双排单层<FONT face="Times New Roman"> </FONT>三排单层<FONT face="Times New Roman"> </FONT>双排双层<FONT face="Times New Roman"> </FONT>三排双层<BR>弯矩（<FONT face="Times New Roman">KN·M</FONT>）<FONT face="Times New Roman"> 788.2 1576.4 2246.4 3265.4 4653.2 1687.5 3375.0 4809.4 6750.0 9618.8<BR></FONT>剪力（<FONT face="Times New Roman">KN</FONT>）<FONT face="Times New Roman"> 245.2 490.5 698.9 490.5 698.9 245.2 490.5 698.9 490.5 698.9<BR><BR>“<st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="321" UnitName="”">321”</st1:chmetcnv></FONT>钢桥<BR><FONT face="Times New Roman"> </FONT>弦杆截面积<FONT face="Times New Roman"> A</FONT>（<FONT face="Times New Roman">cm2</FONT>）：<FONT face="Times New Roman">2×12.74=25.48<BR></FONT>弦杆惯矩<FONT face="Times New Roman"> Ix</FONT>（<FONT face="Times New Roman">cm4</FONT>）：<FONT face="Times New Roman">396.6<BR></FONT>弦杆截面模量<FONT face="Times New Roman"> Wx</FONT>（<FONT face="Times New Roman">cm3</FONT>）：<FONT face="Times New Roman">79.4<BR></FONT>自由长度<FONT face="Times New Roman"> Lp</FONT>（<FONT face="Times New Roman">cm</FONT>）：<FONT face="Times New Roman">75<BR> </FONT>长细比<FONT face="Times New Roman"> λ= Lp/r </FONT>：<FONT face="Times New Roman">19<BR></FONT>纵向弯曲系数<FONT face="Times New Roman"> φ</FONT>：<FONT face="Times New Roman">0.953<BR></FONT>弦杆纵向容许受压荷载（<FONT face="Times New Roman">KN</FONT>）：<FONT face="Times New Roman">663<BR>1</FONT>、容许内力指的是跨中弯矩和支点剪力；<BR><FONT face="Times New Roman">2</FONT>、桁架销子双剪状态容许剪力<FONT face="Times New Roman"> 550KN</FONT>（销子直径为<st1:chmetcnv w:st="on" TCSC="0" NumberType="1" Negative="False" HasSpace="False" SourceValue="49.5" UnitName="mm"><FONT face="Times New Roman">49.5mm</FONT></st1:chmetcnv>）；<BR><FONT face="Times New Roman">3</FONT>、弦杆螺栓允许剪力<FONT face="Times New Roman">150KN</FONT>，允许拉力<FONT face="Times New Roman">80KN</FONT>。<BR><FONT face="Times New Roman"> <BR> <BR></FONT>桁架单元杆件性能（单个贝雷片）<BR>杆件名<FONT face="Times New Roman"> </FONT>材料<FONT face="Times New Roman"> </FONT>断面型式<FONT face="Times New Roman"> </FONT>横断面积（<FONT face="Times New Roman">cm2</FONT>）<FONT face="Times New Roman"> </FONT>理论容许承载力（<FONT face="Times New Roman">KN</FONT>）<BR>弦杆<FONT face="Times New Roman"> 16Mn 2</FONT>根槽<FONT face="Times New Roman">10</FONT>背靠背<FONT face="Times New Roman"> 2×12.74 560<BR></FONT>竖杆<FONT face="Times New Roman"> 16Mn 8#</FONT>工字钢<FONT face="Times New Roman"> 9.52 210<BR></FONT>斜杆<FONT face="Times New Roman"> 16Mn 8#</FONT>工字钢<FONT face="Times New Roman"> 9.52 171.5<o:p></o:p></FONT></P>| 欢迎光临 【天端--工程在线】 (http://sqdadi.com/bbs/) | Powered by Discuz! 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