畢業(yè)設(shè)計外文翻譯--鋼結(jié)構(gòu)設(shè)計規(guī)范

1、<p><b>　　畢業(yè)設(shè)計</b></p><p><b>　　外文資料翻譯</b></p><p>　　原文題目：　　鋼結(jié)構(gòu)設(shè)計規(guī)范 GB50017-2003 English Version　　　　　　　　　　　　　　　　　　　　　 </p><p>　　譯文題目： 鋼結(jié)構(gòu)設(shè)計規(guī)范 GB5001

2、7-2003 　　　　　　　　　 </p><p>　　院系名稱： 土木建筑學(xué)院 專業(yè)班級： 土木工程0901 </p><p>　　學(xué)生姓名： 王振永　 　 學(xué) 號： 200948040115 </p><p>　　指導(dǎo)教師： 陳東

3、兆 　 教師職稱： 副教授　　　　　　 </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　附件1：外文資料翻譯譯文</p><p>　　鋼結(jié)構(gòu)設(shè)計規(guī)范 GB50017</p><p><b>　　3.4 設(shè)計指數(shù)</b></p><p>　　

4、3.4.1鋼的強(qiáng)度設(shè)計值應(yīng)根據(jù)鋼的厚度或者直徑從表格3.4.1-1中查取。鋼鑄件的強(qiáng)度設(shè)計值應(yīng)從3.4.1-2表格中查詢。連接強(qiáng)度的設(shè)計值應(yīng)該通過3.4.1-5從表格3.4.1-3中查取。</p><p>　　表3.4.1-1鋼材強(qiáng)度設(shè)計值</p><p>　　備注：表中厚度表示計算點(diǎn)的鋼材厚度，對于軸心力的作用主要是指截面中較厚的板件區(qū)域。</p><p>　　表

5、3.4.1-2 鋼鑄件的強(qiáng)度設(shè)計值</p><p>　　表3.4.1-3焊縫強(qiáng)度設(shè)計值</p><p>　　備注：1.用于自動和半自動焊的焊條和焊劑應(yīng)保證熔敷金屬的力學(xué)性能 不低于現(xiàn)行國家標(biāo)準(zhǔn)《埋弧焊用碳鋼焊絲和焊劑》GB/T 5293和《低合金鋼埋弧焊用焊劑》GB/T 12470中的相關(guān)規(guī)定。</p><p>　　2.焊縫的質(zhì)量等級應(yīng)符合現(xiàn)行國家標(biāo)準(zhǔn)《鋼結(jié)構(gòu)工程施

6、工質(zhì)量驗收工程規(guī)范》GB 50205的規(guī)定。對厚度小于8mm的對接焊縫型的鋼材不應(yīng)采用超聲波探傷來確定焊縫質(zhì)量等級。</p><p>　　3.，在彎曲部分的對接焊縫，把fcw作為受壓區(qū)的強(qiáng)度設(shè)計值，把ftw作為手拉去的強(qiáng)度設(shè)計值。</p><p>　　4，表中的厚度是指計算位置的鋼材厚度，對于軸心受拉和軸心受壓構(gòu)件是指構(gòu)件中較厚板件的厚度。</p><p>　　表3

7、.4.1-4 螺栓連接的強(qiáng)度設(shè)計值（N/mm2）</p><p>　　備注：1、A級螺栓用于螺栓的d<=24mm和l<=10d或l<=150mm（取較小值）；B級螺栓d>=24mm或者l>=10d或l>=150mm（取較小值），d是公稱直徑，l是螺桿的公稱長度。</p><p>　　2、A、B級螺栓孔的精度和孔壁表面的粗糙度，C級螺栓的允許偏差和孔壁表面

8、的粗糙度應(yīng)符合現(xiàn)行國家標(biāo)準(zhǔn)《鋼結(jié)構(gòu)工程施工質(zhì)量驗收工程規(guī)范》GB 50205的規(guī)定。</p><p>　　表3.4.1-5鉚釘連接強(qiáng)度設(shè)計值</p><p><b>　　備注：</b></p><p>　　1、屬于下列情況的為一類孔：</p><p>　　1）在裝備好的構(gòu)件上按設(shè)計要求的孔徑鉆成的孔；</p>

9、<p>　　2）在單個零件和構(gòu)件上按設(shè)計要求用鉆磨鉆成的孔；</p><p>　　3）在單個零件上先鉆成或者充成較小的孔徑，然后在裝配好的構(gòu)件上擴(kuò)鉆成設(shè)計直徑的孔。</p><p>　　2，在單個零件上一次沖成或不用鉆模直接鉆成的孔是二類孔。</p><p>　　3.4.2在下列情況的結(jié)構(gòu)或者連接時，在條款3.4.1中規(guī)定的設(shè)計值應(yīng)該乘以一個相應(yīng)的折減

10、系數(shù)。</p><p>　　1、單面連接的單角鋼</p><p>　　1）按照軸心受力計算強(qiáng)度和連接，乘以系數(shù)0.85</p><p>　　2）按軸心受壓構(gòu)件計算穩(wěn)定性</p><p>　　等邊角鋼乘以系數(shù) 0.6+0.0015a，但不大于1</p><p>　　以短邊相連的不等邊角鋼連接，乘

11、以系數(shù) 0.5+0.0025a，但不大</p><p><b>　　于1 </b></p><p>　　以長邊相連的不等邊角鋼相連，乘以系數(shù) 0.7</p><p>　　a表示細(xì)長比，對于一個中部沒有連接的單角鋼壓桿，按最小的回</p><p>　　轉(zhuǎn)半徑計算，當(dāng)a<20時，取a=20</p&g

12、t;<p>　　2、無墊板的單面施焊對接焊縫，乘以系數(shù) 0.85</p><p>　　在地面以上的不利條件下的焊接和鉚釘連接的構(gòu)件，乘以系數(shù) 0.9</p><p>　　埋頭孔和半埋頭孔的鉚釘連接乘以系數(shù) 0.8</p><p>　　備注：當(dāng)這些條件中的幾個同時發(fā)生時，相應(yīng)的折減系數(shù)也應(yīng)該連乘。</p>

13、<p>　　3.4.3軋制的構(gòu)件和鋼鑄構(gòu)件的物理性能指標(biāo)應(yīng)根據(jù)表格3.4.3</p><p>　　表3.4.3 軋制構(gòu)件和鋼鑄件的物理性能指標(biāo)</p><p>　　3.5結(jié)構(gòu)或構(gòu)件變形的規(guī)定</p><p>　　3.5.1 為了不影響適用性，不影響結(jié)構(gòu)或者構(gòu)件的外觀，在設(shè)計時對它們的變形（撓曲或側(cè)移）作相應(yīng)的限值。按照一般的規(guī)定，結(jié)構(gòu)或構(gòu)件變形的限制

14、件本規(guī)范附錄A，當(dāng)有工程經(jīng)驗或者特殊要求時，這樣的限值可以在不影響正常的使用和外觀要求的條件下，作適當(dāng)?shù)男薷?lt;/p><p>　　3.5.2在鋼結(jié)構(gòu)或構(gòu)件的變形計算中，可以不考慮螺栓孔（或鉚釘孔）面積減少的影響。</p><p>　　3.5.3為了改善外觀和使用條件，可以將橫向受力構(gòu)件預(yù)先起拱，起拱的大小根據(jù)實際情況而定，一般情況下是以恒載標(biāo)準(zhǔn)值加二分之一活載標(biāo)準(zhǔn)值所產(chǎn)生的撓度值。當(dāng)僅為改

15、善外觀條件時，構(gòu)件撓度應(yīng)取結(jié)構(gòu)在恒載和活載標(biāo)準(zhǔn)值作用下的撓度計算值減去預(yù)拱值。</p><p><b>　　4 撓曲構(gòu)件的計算</b></p><p><b>　　4.1強(qiáng)度</b></p><p>　　4.1.1 在主平面內(nèi)受彎構(gòu)件的彎曲強(qiáng)度應(yīng)按下式計算（考慮構(gòu)件屈曲強(qiáng)度的參見本規(guī)范4.4.1）：</p>

16、<p><b>　　(4.1.1)</b></p><p>　　式中 Mx ，My——在同一位置處x軸和y軸的彎矩（對工字型截面，x軸為強(qiáng)軸，y軸為</p><p><b>　　弱軸）</b></p><p>　　Wnx，Wny——對x軸和y軸的凈截面模量</p><p>　　rx、ry

17、 ——塑性調(diào)整系數(shù)，對工字型rx = 1.05 ，ry = 1.2，對箱型rx，ry </p><p>　　= 1.05，對于其它的類型看表5.2.1</p><p>　　:f —— 鋼構(gòu)件彎曲強(qiáng)度設(shè)計值</p><p>　　當(dāng)梁的受壓翼緣的寬度與其厚度的壁紙大于，但小于時，rx應(yīng)取1.0，fy為鋼材對應(yīng)等級的屈服點(diǎn)的強(qiáng)度。</p><p&

18、gt;　　對也要求抗疲勞驗算的梁，rx，ry = 1.0</p><p>　　4.1.2 在主平面內(nèi)受彎的實腹構(gòu)件的抗剪強(qiáng)度應(yīng)按下式計算。（考慮構(gòu)件屈曲強(qiáng)度的參見本規(guī)</p><p>　　范4.4.1）： </p><p><b>　　(4.1.2)</b></p><p>　　式中：V ——在計算區(qū)域的腹板位置的剪力

19、</p><p>　　S ——在計算剪應(yīng)力處以上毛截面對中和軸的面積距</p><p>　　I ——毛截面的慣性矩</p><p><b>　　'tw——腹板厚度</b></p><p>　　'fv——鋼材的剪力強(qiáng)度設(shè)計值</p><p>　　4.1.3當(dāng)在梁的上翼緣受有沿腹板平面

20、的的集中荷載作用時，并且沒有足夠的支撐加勁肋時，在；腹板計算高度上的局部承壓強(qiáng)度應(yīng)按下式計算：</p><p><b>　　(4.1.3－1)</b></p><p>　　式中：F ——集中荷載，在動荷載作用下考慮到動力系數(shù)；</p><p>　　——集中荷載加強(qiáng)系數(shù)，對重要的吊車主梁 =1.35 ，對其它的橫</p><p

21、>　　梁或者主梁 =1.0</p><p>　　Lz ——在腹板上邊緣計算高度上的集中荷載虛擬的分布長度：</p><p>　　Lz = a + 5hy +2</p><p>　　'a ——沿著梁跨度方向的集中荷載的承壓長度，對于鋼軌上的輪壓取</p><p><b>　　50mm</b></p>

22、;<p>　　'hy——自主梁或橫梁頂面至腹板計算高度上邊緣的距離</p><p>　　——鋼軌的高度，對于頂上沒有鋼軌的梁取 =0</p><p>　　'f ——鋼構(gòu)件的抗壓強(qiáng)度設(shè)計值</p><p>　　在梁的支座處，當(dāng)沒有加勁肋支撐時，在它有效高度的低腹板處的局部壓力也應(yīng)該用公式（4.1.3-1），取 =1.0。支座最終反作用力的

23、分布長度由公式（4.1.3-2）和根據(jù)支撐尺寸決定。</p><p>　　注：腹板的有效高度 ho是：對于軋制主梁：為腹板與上、下翼緣相連接處兩內(nèi)弧起點(diǎn)間的距離；對于焊接下翼緣與主梁，是腹板的高度；對鉚接（或高強(qiáng)螺栓）連接的主梁：為上、</p><p>　　腹板連接的鉚釘（或高強(qiáng)螺栓）線間的最近距離（見圖4.3.2）。</p><p>　　4.1.4梁的腹板在計算高

24、度邊緣處，有相當(dāng)大的正常正應(yīng)力、剪應(yīng)力和局部壓應(yīng)力，（或相當(dāng)大的正應(yīng)力和切應(yīng)力）（例如在連續(xù)梁中部支座處或梁的翼緣截面改變出等）存在時，其它的折算盈利應(yīng)按下式計算：</p><p><b>　　(4.1.4－1)</b></p><p>　　式中：, , c—在同一節(jié)點(diǎn)的有效的腹板計算高度邊緣，同時產(chǎn)生的正</p><p>　　應(yīng)力、剪應(yīng)力和局

25、部壓應(yīng)力。剪應(yīng)力和局部壓應(yīng)力應(yīng)分別由公式（4.1.2）和公式</p><p>　?。?.1.3-1）計算。正應(yīng)力按下式計算：</p><p><b>　　(4.1.4－2)</b></p><p>　　和以拉應(yīng)力為整治，當(dāng)是壓應(yīng)力時為負(fù)值；</p><p>　　In ——橫梁的凈截面慣性矩</p><

26、p>　　'y1——從計算點(diǎn)到梁中軸線的距離</p><p>　　——計算折算應(yīng)力的設(shè)計值放大系數(shù)，當(dāng)和的符號不同時，取=1.2，</p><p>　　當(dāng)和的符號相同時，或者當(dāng)=0時， =1.1</p><p><b>　　4.2整體穩(wěn)定</b></p><p>　　4.2.1 當(dāng)出現(xiàn)下列之一條件時，可以不考

27、慮梁的整體穩(wěn)定計算：</p><p>　　1、當(dāng)有穩(wěn)定的平板（加固的混凝土平板或鋼材平板）與受壓翼緣相連接，可以約束它</p><p><b>　　的側(cè)移時。</b></p><p>　　2、當(dāng)由軋制的H型鋼或I字鋼的受壓翼緣的自由長度與受壓翼緣的寬度的比例不超</p><p>　　過表4.2.1所給出的值時。</

28、p><p>　　表4.2.1 僅由軋制的H型鋼或I字鋼不需要計算受壓穩(wěn)定性的</p><p>　　受壓翼緣的自由長度與寬度的最大l1/b1值</p><p>　　備注：在表4.2.1中除Q235鋼的其它不需要計算的最大的l1/b1的比值應(yīng)取Q235鋼的數(shù)字乘以</p><p>　　對有跨內(nèi)買有側(cè)移支撐的梁，l1是跨長對跨內(nèi)有側(cè)移支撐的梁，l1是兩

29、個支撐點(diǎn)的距離（梁的支座處被看做有支撐）</p><p>　　4.2.2 除了表4.2.1中的情況外，受彎的H型鋼和I字鋼在主平面內(nèi)的整體穩(wěn)定性應(yīng)按下式計算：</p><p><b>　　(4.2.3) </b></p><p>　　式中：Wx，Wy——按受壓纖維確定的對x軸和y軸的毛截面模量</p><p>　　——受

30、彎構(gòu)件的強(qiáng)軸的壓桿穩(wěn)定系數(shù)，與4.2.2條的一樣</p><p>　　4.2.4 不符合4.2.1條情況的整體箱型梁，其界面尺寸（圖4.2.4）應(yīng)滿足h/b<=6,l1/b1<=95(235/fy).</p><p>　　符合上述規(guī)定的箱型截面簡直了，可以不用計算整體穩(wěn)定性。</p><p>　　Figure 4.2.4 Box-section</

31、p><p>　　4.2.5 在梁的支座處，應(yīng)采取構(gòu)造措施，應(yīng)阻止梁端截面的扭轉(zhuǎn)。</p><p>　　4.2.6用作減小受壓翼緣自由長度的側(cè)向支撐，其支撐應(yīng)力將梁的受壓翼緣視為軸心受壓構(gòu)件按5.1.7條款計算。</p><p><b>　　4.3局部穩(wěn)定</b></p><p>　　4.3.1 承載靜力荷載或間接荷載的組合梁

32、應(yīng)考慮腹板屈曲后的強(qiáng)度，根據(jù)規(guī)范4.4的規(guī)定計算其抗彎和抗剪的承載力；而直接承受動荷載以及類似構(gòu)件或其它不考慮屈曲后強(qiáng)度的組合梁，則應(yīng)該按規(guī)范的第4.3.2條款的規(guī)定布置加勁肋。當(dāng)時，尚應(yīng)按本規(guī)范第4.3.3跳空開至第4.3.5條款的規(guī)定計算腹板的穩(wěn)定性。</p><p>　　在輕級、中級工作的吊車梁的腹板穩(wěn)定性計算時，吊車梁輪壓的設(shè)計值可以乘以折減系數(shù)0.9。</p><p>　　4.3

33、.2組合梁中的腹板的加勁肋須滿足以下的預(yù)防措施（圖.4.3.2.):</p><p>　　Figure 4.3.2 Layout of stiffeners</p><p>　　1- transverse stiffeners; 2- longitudinal stiffeners; 3- short stiffeners</p><p>　　當(dāng)

34、ho/tw<=80時，對局部壓應(yīng)力不等于0，為了滿足設(shè)計要求應(yīng)按構(gòu)造配置加勁肋，當(dāng)局部壓應(yīng)力=0時，可以不配置加勁肋。</p><p>　　當(dāng)ho/tw>80時，應(yīng)配置橫向加勁肋。當(dāng)ho/tw>170時（受壓翼緣的扭轉(zhuǎn)受到約束，例如連接有剛性鋪板，阻止振動的板或焊有鋼軌時）或者h(yuǎn)o/tw>150時（受壓翼緣的扭轉(zhuǎn)未受限制）或者需按計算需要時，應(yīng)該在彎曲應(yīng)力較大的受壓區(qū)再另外配置縱向加勁肋。

35、對于考慮局部壓應(yīng)力的梁，在必要的時候也應(yīng)在受壓區(qū)配置短的加勁肋。</p><p>　　無論任何條件下，ho/tw不應(yīng)該超過250</p><p>　　綜上所述的，ho時有效的腹板計算高度（對于單軸對稱梁，當(dāng)判斷時候需要配置加勁肋時，ho應(yīng)取腹板受壓區(qū)高度ho的2倍），tw為腹板的厚度。</p><p>　　3、當(dāng)在梁的支座處和在承受較大的集中固定荷載的上翼緣處，均應(yīng)

36、設(shè)置支撐加勁肋。</p><p>　　4.3.3對設(shè)置橫向加勁肋的梁翼緣板（圖.4.3.2a），其局部壓應(yīng)力應(yīng)用下列的表達(dá)式計算：</p><p><b>　　(4.3.3－1)</b></p><p>　　式中： —在所計算腹板區(qū)隔內(nèi)，由平均彎矩引起的在腹板計算高度邊緣引起的</p><p><b>　　應(yīng)力

37、；</b></p><p>　　—在所計算腹板區(qū)隔內(nèi)，由平均剪力引起的在腹板計算高度邊緣引起的的</p><p>　　平均剪應(yīng)力，, hw表示腹板高度；</p><p>　　c—在腹板計算高度邊緣的有效的局部壓應(yīng)力，用公式(4.1.3－1)來計算，但</p><p><b>　　取=1.0;</b></

38、p><p>　　cr, cr, c, cr—由單獨(dú)作用下的應(yīng)力引起的臨界壓應(yīng)力、剪切力和局部壓應(yīng)</p><p>　　力，由下列的公式計算</p><p>　　1)cr 由下列的公式計算</p><p><b>　　當(dāng) b≤0.85</b></p><p>　　cr=f

39、 (4.3.3－2a)</p><p>　　當(dāng) 0.85<b≤1.25</p><p>　　cr=[1-0.75(b-0.85)]f (4.3.3－2b)</p><p><b>　　當(dāng) b>1.25</b></p><p&

40、gt;　　(4.3.3－2c)</p><p>　　式中 b—在腹板受彎計算中的正常高厚比；</p><p>　　當(dāng)梁的受壓翼緣受到扭轉(zhuǎn)的約束時：</p><p>　　(4.3.3－2d)</p><p>　　當(dāng)梁的受壓翼緣未受到扭轉(zhuǎn)的約束時：</p><p>　　(4.3.3－2e)</p><p

41、>　　式中 hc—梁的腹板彎曲受壓區(qū)的高度，對雙軸對稱的截面2hc= h0 </p><p>　　cr 由下列的公式計算：</p><p><b>　　當(dāng) s≤0.8</b></p><p>　　cr=fv (4.3.3－3a)</p><p&g

42、t;　　當(dāng) 0.8<s≤1.2</p><p>　　(4.3.3－3b)</p><p>　　當(dāng) s>1.2 (4.3.3－3c)</p><p>　　式中 s—用于腹板的受剪計算時通用的高后比</p><p>　　當(dāng) a/h0≤1.0<

43、;/p><p>　　(4.3.3－3d)</p><p>　　當(dāng) a/h0>1.0</p><p>　　(4.3.3－3e)</p><p>　　c,cr由下列的公式計算： </p><p>　　當(dāng) c≤0.9</p><p>　　c, cr =f

44、 (4.3.3－4a)</p><p>　　當(dāng) 0.9<c≤1.2</p><p>　　c,cr=[1-0.79(c-0.9)]f (4.3.3－4b)</p><p><b>　　當(dāng) c>1.2</b></p><p&

45、gt;　　(4.3.3－4c)</p><p>　　式中 c—在局部壓力作用下的翼緣的通用高厚比。</p><p>　　當(dāng) 0.5≤a/h0≤1.5</p><p>　　(4.3.3－4d)</p><p>　　當(dāng) 1.5<a/h0≤2.0 </p><p>　　(4.3.3－4e)</p>&l

46、t;p>　　4.3.4 既有橫向加勁肋 又有縱向加勁肋加強(qiáng)的腹板（圖.4.3.2b，c），用下列的公式檢測局部穩(wěn)定性：</p><p>　　1 受壓翼緣與縱向加勁肋之間的區(qū)格</p><p><b>　　(4.3.4－1)</b></p><p>　　式中 cr1, cr1, c,cr1 由下列的公式計算</p><

47、;p>　　cr1 r由下列的公式（4.3.3—2）計算，但是b 改用下列的b1 代替</p><p>　　當(dāng)梁的受壓翼緣扭轉(zhuǎn)受到約束時：</p><p>　　(4.3.4－2a)</p><p>　　當(dāng)梁的受壓翼緣扭轉(zhuǎn)受到約束時：</p><p>　　(4.3.4－2b)</p><p>　　式中 h1—縱向加

48、勁肋至腹板計算高度受壓邊緣的距離</p><p>　　2）cr1 由下列的公式（4.3.3—3）計算，并將式中的h1代替ho，</p><p>　　3) c,cr1 由下列的公式（4.3.3—2）計算，并將式中的c1代替b ，</p><p>　　當(dāng)梁的受壓翼緣扭轉(zhuǎn)受到約束時：</p><p>　　(4.3.4－3a)</p>

49、<p>　　當(dāng)梁的受壓翼緣扭轉(zhuǎn)未受到約束時：</p><p>　　(4.3.4－3b)</p><p>　　2 受拉翼緣與縱向加勁肋之間的區(qū)格</p><p><b>　　(4.3.4－4)</b></p><p>　　式中 2— 在所計算的區(qū)格內(nèi)由平均的彎矩所產(chǎn)生的腹板內(nèi)在縱向加勁肋處的彎曲</p>

50、;<p><b>　　正應(yīng)力;</b></p><p>　　c2—在縱向加勁肋處的腹板的橫向正應(yīng)力，取0.3c.</p><p>　　1）cr2 由下列的公式（4.3.3—2）計算，并用b2代替b </p><p><b>　　(4.3.4－5)</b></p><p>　　2）cr

51、2 由下列的公式（4.3.3—3）計算，并用h2代替h0 (h2= h0-h1).</p><p>　　3）c,cr2 由下列的公式（4.3.3—4）計算，并用h2代替h0， 當(dāng) a/h2>2時取a/h2=2 </p><p>　　附件2：外文原文（出自:鋼結(jié)構(gòu)設(shè)計規(guī)范 GB50017-2003）</p><p>　　3.4 Desi

52、gn indices</p><p>　　3.4.1 The design value of steel strength shall be taken from Table 3.4.1-1 according to the steel thickness or diameter. The design value of strength of cast steel parts shall be taken fr

53、om Table 3.4.1-2. The design value of connection strength shall be taken from Tables 3.4.1-3 through 3.4.1-5.</p><p>　　Table 3.4.1-1 Design value of steel strength (N/mm2)</p><p>　　Note: Thickne

54、ss in this table denotes the steel thickness at the calculation location, for members subject to axial force, it is the thickness of the thicker plate element of the section.</p><p>　　Table 3.4.1-2 Design va

55、lue of cast steel strength(N/mm2)</p><p>　　Table 3.4.1-3 Design value of weld strength (N/mm2)</p><p>　　Note : 1. The electrode wire and flux used for automatic and semi-automatic welding shall

56、 be guaranteed that the mechanical properties of the deposited metal is not lower than the requirement of the current national standards “Carbon steel electrodes and fluxes for submerged arc welding”GB/T5293 and “ Fluxes

57、 for the submerged arc welding of low alloy steel” GB/T12470.</p><p>　　2. The weld quality class shall comply with the requirements of the current national standard “Code for acceptance of construction quali

58、ty of steel structures” GB 50205. For butt welds of steel components thinner than 8mm ultrasonic flaw detector shall not be used to determine the weld quality class.</p><p>　　3. For butt welds subject to fle

59、xion, take as the design value of strength in compression zone and in tension zone.</p><p>　　4. “Thickness” in this table denotes the steel thickness at the location of calculation. For members in axial te

60、nsion and axial compression it is the thickness of the thicker plate element of the section.</p><p>　　Note ：1. Grade A bolts are used for bolts with d≤24mm and l≤10d or l≤150mm (take the lesser value); grad

61、e B bolts are used for bolts with either d >24mm or l>10d or l >150mm (take the lesser value). d is the nominal diameter. l is the nominal length of bolt shank.</p><p>　　2. The precision and the su

62、rface roughness of holes of grade A, B bolts and the tolerance and surface roughness of holes of grade C bolts shall meet the requirements of the current national standard “Code for acceptance of construction quality of

63、steel structures” GB 50205.</p><p>　　Table 3.4.1-5 Design value of riveted connection strength (N/mm2)</p><p>　　Note: 1. Holes made by the following processes belong to class I:</p><p

64、>　　1) holes drilled to the design diameter on assembled members;</p><p>　　2) holes drilled to the design diameter separately on individual elements and members by using drilling template;</p><p

65、>　　3) holes drilled or punched to a smaller diameter on individual elements and reamed afterwards to the design diameter on assembled member.</p><p>　　2. Holes punched or drilled without template to the d

66、esign diameter on individual elements belong to class II.</p><p>　　3.4.2 The design value of strength specified in Clause 3.4.1 shall be multiplied by a relevant reduction factor in the following situations

67、of member and connection calculation:</p><p>　　1. Single angle connected by one leg</p><p>　　1) for checking member and connection strength as axially loaded, multiply by 0.85</

68、p><p>　　2) for checking stability as an axially loaded compression member</p><p>　　Equal leg angles, multiply by 0.6+0.0015λ, but not larger than 1.0</p><p>

69、　　Unequal leg angles connected by short leg, multiply by 0.5+0.0025λ, but not larger than 1.0</p><p>　　Unequal leg angles connected by long leg, multiply by 0.7</p&g

70、t;<p>　　where λ is the slenderness ratio, which shall be determined by the least radius of gyration for a single angle compression member without intermediate connection. Assume λ=20 when λ<20.</p><p

71、>　　2. Butt weld performed by welding from one side without backing plate, multiply by 0.85</p><p>　　3. Welded and riveted erection connections made high above the ground in unfavorable conditi

72、ons, multiply by 0.9</p><p>　　4. Countersunk and semicountersunk riveted connection, multiply by 0.8<

73、;/p><p>　　Note: When several of these situations occur simultaneously, the relevant reduction factors shall be multiplied successively.</p><p>　　3.4.3 The indices of physical properties of rolled a

74、nd cast steel shall be taken according to Table 3.4.3</p><p>　　Table 3.4.3 Indices of physical properties of rolled and cast steel</p><p>　　3.5 Provisions for deformation of structures and stru

75、ctural members</p><p>　　3.5.1 In order not to impair the serviceability, nor to affect the appearance of structures and structural members, their deformation (deflection or lateral drift) shall comply with t

76、he relevant limiting values in designing. The allowable values of deformation, as a general rule, are specified in Appendix A of this Code. The values therein may be suitably modified in consideration of practical experi

77、ences or to meet a specific demand, provided the serviceability is not impaired nor the appearanc</p><p>　　3.5.2 Reduction of sectional area by bolt (or rivet) holes may not be taken into account in the defo

78、rmation calculation of steel structures and members.</p><p>　　3.5.3 In order to improve the appearance and the service condition, members subject to transverse forces may be given a predetermined camber, who

79、se magnitude shall be set according to practical need and usually taken as the deflection caused by the unfactored dead load plus one half unfactored live load. In the case of solely improving the appearance, the member

80、deflection shall be taken as that calculated from the unfactored dead and live load and minus the camber.</p><p>　　4 Calculation of flexural members</p><p>　　4.1 Strength</p><p>　　4

81、.1.1 The bending strength of solid web members bent in their principal planes shall be checked as follows (for members taking account of web post-buckling strength see Clause 4.4.1 of this Code):</p><p><

82、b>　　(4.1.1)</b></p><p>　　where Mx, My—bending moments about x- and y- axes at a common section (for I-section, x-axis is the strong axis and y is the weak axis);</p><p>　　Wnx, Wny—net

83、 section moduli about x- and y-axis;</p><p>　　x, y—plasticity adaptation factors, x =1.05, y =1.20 for I-section, x, y=1.05 for box section, see Table 5.2.1for other sections;</p><p>　　f —design

84、 value of bending strength of steel.</p><p>　　When the ratio of the free outstand of the compression flange to its thickness is larger than, but not exceeding, x shall be taken as 1.0. fy is the yield streng

85、th of the material indicated by the steel grade.</p><p>　　For beams requiring fatigue checking, x=y =1.0 should be used.</p><p>　　4.1.2 The shear strength of solid web members bent in their prin

86、cipal plane shall be checked by the following formula (for members taking account of web post-buckling strength, see Clause 4.4.1 of this Code):</p><p><b>　　(4.1.2)</b></p><p>　　wher

87、e V—shear force in the calculated section along the plane of web;</p><p>　　S—static moment about neutral axis of that part of the gross section above the location where shear stress is calculated;</p>

88、<p>　　I—moment of inertia of gross section;</p><p>　　tw—web thickness;</p><p>　　fv—design value of shear strength of steel.</p><p>　　4.1.3 When a concentrated load is acting

89、along the web plane on the upper flange of the beam, and that no bearing stiffener is provided at the loading location, the local compressive stress of the web at the upper edge of its effective depth shall be computed a

90、s follows:</p><p><b>　　(4.1.3－1)</b></p><p>　　where F—concentrated load, taking into account the impact factor in case of dynamic loading;</p><p>　　—amplification coeff

91、icient of the concentrated load, =1.35 for heavy duty crane girder; =1.0 for other beams and girders;</p><p>　　lz—assumed distribution length of the concentrated load on the upper edge of the effective

92、 web depth taken as:</p><p><b>　　(4.1.3－2)</b></p><p>　　a—bearing length of the concentrated load along the beam span, taken as 50mm for wheel loading on rail;</p>

93、<p>　　hy—distance from the top of girders or beams to the upper edge of the effective web depth;</p><p>　　hR—depth of the rail, hR =0 for beams without rail on top;</p><p>　　f—design value

94、 of compressive strength of steel.</p><p>　　At the beam support, when no bearing stiffener is provided, the local compressive stress in the web at its lower edge of effective depth shall also be checked by F

95、ormula (4.1.3－1), with take as 1.0. The distribution length of the end reaction shall be determined with reference to Formula(4.1.3－2) and according to the dimensions of the support.</p><p>　　Note: The effe

96、ctive web depth h0 is:</p><p>　　For rolled beams: the distance between the web toes of the fillets joining the web with the upper and lower flanges;</p><p>　　For welded girders: the depth of the

97、 web;</p><p>　　For riveted（or high-strength bolted）girders: the distance between the nearest gauge lines of rivets (or high-strength bolts) connecting the web with the upper and lower flanges (see Fig. 4.3.2

98、).</p><p>　　4.1.4 In case comparatively large normal stress , shear stress , and local compressive stress c(or comparatively large and) exist simultaneously at the edge of the effective web depth of build–up

99、 girders, e. g. at the intermediate support of a continuous girder or at a section where the flange changes its dimensions, the reduced stress shall be checked by the following expression </p><p><b>　　

100、(4.1.4－1)</b></p><p>　　where , , c—normal stress, shear stress and local compressive stress occurring simultaneously at a same point on the edge of effective web depth. and c are calculated by Formula

101、e (4.1.2) and (4.1.3－1) respectively, while is determined as follows:</p><p><b>　　(4.1.4－2)</b></p><p>　　and c are taken as positive while being tensile and negative while compressi

102、ve;</p><p>　　In—moment of inertia of the net beam section;</p><p>　　y1—distance from the calculated point to the neutral axis of the beam section;</p><p>　　1—amplification coefficie

103、nt of design value of strength for reduced stress, 1=1.2 when and c are of different signs, 1=1.1 when and c are of the same sign or when c =0.</p><p>　　4.2 Overall stability</p><p>　　4.2.1 Ca

104、lculation of the overall stability of the beams may not be needed when one of the following situations takes place:</p><p>　　1. A rigid decking (reinforced concrete slab or steel plate) is securely connected

105、 to the compression flange of the beam and capable of preventing its lateral deflection;</p><p>　　2. The ratio of the unsupported length, l1, of the compression flange of a simply supported rolled H- or unif

106、orm I-section beam to its flange width, b1, does not exceed the values given in Table 4.2.1.</p><p>　　Table 4.2.1 Maximum l1/b1 values of simply supported rolled H- or uniform I-section beams to avoid checki

107、ng for overall stability</p><p>　　Note: The maximum l1/b1values of beams made of steel grade other than those shown in Table 4.2.1 shall be that of Q235 steel multiplied by.</p><p>　　For beams d

108、evoid of lateral support within the span, l1 is the span length; for those provided with lateral supports within the span, l1 is the distance between these supports (beam bearings are considered as supports).</p>

109、<p>　　4.2.2 Except for the situations specified in Clause 4.2.1, members bent in their principal plane of largest rigidity shall be checked for overall stability as follows:</p><p><b>　　(4.2.2)<

110、;/b></p><p>　　where Mx—maximum bending moment about the strong axis;</p><p>　　Wx—gross section modulus of the beam with respect to compression fibers;</p><p>　　b—overall stabili

111、ty factor determined according to Appendix B.</p><p>　　4.2.3 Except for the situations specified in Clause 4.2.1, H- and I-section members bent in their two principal planes shall be checked for overall stab