谁知道先张预应力空心板梁的计算方法和在张拉时应该注意哪方面的... [复制链接]

谁知道的说一下  谢谢n~F3…kabbs.3c3t.com÷h I±õ Ä

你的计算是指哪方面？设计吗？n~F3…kabbs.3c3t.com÷h I±õ Ä
张拉时的注意事项：主要是张拉前准备工作多，要检查到位，张拉过程中很简单，以应力控制为主，伸长量复核，还有就是安全，不要站在顶的正面，一旦束断了，那可比子弹还可怕．n~F3…kabbs.3c3t.com÷h I±õ Ä

2、张拉台座验算n~F3…kabbs.3c3t.com÷h I±õ Ä
1、抗倾覆验算                        n~F3…kabbs.3c3t.com÷h I±õ Ä
    G1=    756    B=    5.04        P=    7500    n~F3…kabbs.3c3t.com÷h I±õ Ä
    L1=    3.6    H=    2                n~F3…kabbs.3c3t.com÷h I±õ Ä
    G2=    132    h=    0.5                n~F3…kabbs.3c3t.com÷h I±õ Ä
    L2=    1.05    h1=    0.15                n~F3…kabbs.3c3t.com÷h I±õ Ä
平衡力矩：    Mr  =    G1L1+    G2L2=    2860.5    KN        n~F3…kabbs.3c3t.com÷h I±õ Ä
倾覆力矩：    Mdv =    Ph1=    1124.9    KN                n~F3…kabbs.3c3t.com÷h I±õ Ä
抗倾覆安全系数：    K =    Mr  /  Mdv =    2.5    >1.5    (安全)        n~F3…kabbs.3c3t.com÷h I±õ Ä
2、抗滑移验算                        n~F3…kabbs.3c3t.com÷h I±õ Ä
台面抵抗力：    Nˊ=    300*B=    1512    KN                n~F3…kabbs.3c3t.com÷h I±õ Ä
台座与土的摩阻力：    F     =    μ（G1+G2）=    0.35    *    888     =310.9    KNn~F3…kabbs.3c3t.com÷h I±õ Ä
台座底部的被动土压力：    Pep  =    γH*2.67=    96.1    KN/m2                n~F3…kabbs.3c3t.com÷h I±õ Ä
台座板底部的土压力：    Pˊ=    hPep/H=    24.0    KN/m2                n~F3…kabbs.3c3t.com÷h I±õ Ä
台座底部和座面上土压力的合力：                        n~F3…kabbs.3c3t.com÷h I±õ Ä
    Ep=    （Pep+Pˊ）（H-h）B/2    =    454.2    KN    n~F3…kabbs.3c3t.com÷h I±õ Ä
抗滑移安全系数：    K=    （Nˊ+F + Ep）/ P    =    0.30    <1.3(不安全)n~F3…kabbs.3c3t.com÷h I±õ Ä
      抗滑移安全系数过小，采取增设3根支撑梁的措施确保抗滑移安全系数。    n~F3…kabbs.3c3t.com÷h I±õ Ä
3、牛腿配筋计算                                n~F3…kabbs.3c3t.com÷h I±õ Ä
               h0=2000-100=1900mm                        n~F3…kabbs.3c3t.com÷h I±õ Ä
Ag=ph1/0.85h0fg=    3750*150*1000/0.85*1900*210  =    1659    m2    n~F3…kabbs.3c3t.com÷h I±õ Ä
设计规定：纵向受拉钢筋的最小配筋率Ag/bh0不应小于0.2%。现Ag小于规定,故取n~F3…kabbs.3c3t.com÷h I±õ Ä
Ag=    0.002*500*1900=    1900    mm2    n~F3…kabbs.3c3t.com÷h I±õ Ä
选用6φ25mm钢筋    Ag=    2944=    mm2    （符合要求）        n~F3…kabbs.3c3t.com÷h I±õ Ä
                                n~F3…kabbs.3c3t.com÷h I±õ Ä
4、钢横梁计算：                                n~F3…kabbs.3c3t.com÷h I±õ Ä
q=    P/L=    3750/1.52=    2467.1=    FN/m                n~F3…kabbs.3c3t.com÷h I±õ Ä
钢梁的最大弯距：M=    1/8qL2=    712.5    KNm                    n~F3…kabbs.3c3t.com÷h I±õ Ä
钢梁需要的截面抵抗力为：W=    M/f  =    2261905    mm3        n~F3…kabbs.3c3t.com÷h I±õ Ä
用2根16Mn40b工字钢，    WX =    1140000    ×2 =  2280000  mm3    >    2261905    mm3n~F3…kabbs.3c3t.com÷h I±õ Ä
    (可满足条件)                        n~F3…kabbs.3c3t.com÷h I±õ Ä
钢梁的剪力为：    V=    1/2qL  =      1/2×1752.3×1.52  =    1875    KNn~F3…kabbs.3c3t.com÷h I±õ Ä
钢梁的剪应力为：    τ=    V/F  =    1875000/9410×2=    99.6    Mpa< fv = 185MPan~F3…kabbs.3c3t.com÷h I±õ Ä
钢梁变形值为：    ωmax=    5qL4/384EI=    5×2467.1×15204    /384×2×105×22780×104×2n~F3…kabbs.3c3t.com÷h I±õ Ä
    ωmax=    1.9mm    <L/400=    1520/400=    3.8    mm    n~F3…kabbs.3c3t.com÷h I±õ Ä
    (可满足要求)                        n~F3…kabbs.3c3t.com÷h I±õ Ä
计算式中符号意义：                                n~F3…kabbs.3c3t.com÷h I±õ Ä
G1—      台座外伸部分的重力    n~F3…kabbs.3c3t.com÷h I±õ Ä
L1—      G1点至O点的水平距离    n~F3…kabbs.3c3t.com÷h I±õ Ä
G2—      台座部分的重力    n~F3…kabbs.3c3t.com÷h I±õ Ä
L2—      G2点至O点的水平距离    n~F3…kabbs.3c3t.com÷h I±õ Ä
P—      预应力钢绞线的张拉力    n~F3…kabbs.3c3t.com÷h I±õ Ä
h1—      P作用点至O点的距离    n~F3…kabbs.3c3t.com÷h I±õ Ä
h0—      截面的有效高度    n~F3…kabbs.3c3t.com÷h I±õ Ä
Ag—      纵向受拉及受压钢筋截面面积    n~F3…kabbs.3c3t.com÷h I±õ Ä
q—      承力钢板传给每根钢横梁的均布荷载    n~F3…kabbs.3c3t.com÷h I±õ Ä
f—      钢材的抗拉、抗弯强度    n~F3…kabbs.3c3t.com÷h I±õ Ä
fv—      钢材拉剪强度设计值    n~F3…kabbs.3c3t.com÷h I±õ Ä
E—      钢材的弹性模量    n~F3…kabbs.3c3t.com÷h I±õ Ä
I—      钢梁的贯性矩    n~F3…kabbs.3c3t.com÷h I±õ Ä
12、钢绞线理论伸长值的计算n~F3…kabbs.3c3t.com÷h I±õ Ä
△    L= P •L/ AP•Epn~F3…kabbs.3c3t.com÷h I±õ Ä
P    预应力筋平均张拉力（N）n~F3…kabbs.3c3t.com÷h I±õ Ä
L     预应力筋长度（mm）n~F3…kabbs.3c3t.com÷h I±õ Ä
EP    预应力筋弹性模量（N/mm2）n~F3…kabbs.3c3t.com÷h I±õ Ä
AP    预应力筋截面面积（mm2）n~F3…kabbs.3c3t.com÷h I±õ Ä
生产3片27m空心板的张拉台座台面长89.4mn~F3…kabbs.3c3t.com÷h I±õ Ä
p=187490 (N)n~F3…kabbs.3c3t.com÷h I±õ Ä
EP=1.95×105 (N/mm2)n~F3…kabbs.3c3t.com÷h I±õ Ä
AP=140(mm2)n~F3…kabbs.3c3t.com÷h I±õ Ä
△    L=187490×89400/140×1.95×105 =  614  (mm)n~F3…kabbs.3c3t.com÷h I±õ Ä
1、进入现场必须遵守安全生产十大纪律；n~F3…kabbs.3c3t.com÷h I±õ Ä
2、操作人员对机械的各项技术参数要熟悉，并熟练撑握各项操作技能，方可上岗。n~F3…kabbs.3c3t.com÷h I±õ Ä
3、在放钢绞线之前应把钢绞线用架子固定好并夹紧，避免钢绞线骤然放松弹出伤人。n~F3…kabbs.3c3t.com÷h I±õ Ä
4、在放钢绞线时，应注意架子里的钢绞线是否顺畅，同时要将钢绞线拉直到位，方可切断，防止浪费。n~F3…kabbs.3c3t.com÷h I±õ Ä
5、在安装锚夹具前，应对锚夹具外观进行检查，锚夹具不得有裂纹、伤痕、秀蚀，否则要进行更换。n~F3…kabbs.3c3t.com÷h I±õ Ä
6、在张拉前要检查千斤顶、油泵、压力表是否正常。n~F3…kabbs.3c3t.com÷h I±õ Ä
7、在张拉前要把张拉台两端的安全护栏安装好方能张拉。n~F3…kabbs.3c3t.com÷h I±õ Ä
8、张拉时设立警戒线，和施工无关人员严禁走入警戒线内。n~F3…kabbs.3c3t.com÷h I±õ Ä
9、张拉时不得踩踏攀附油管，油管如有破损要更换。n~F3…kabbs.3c3t.com÷h I±õ Ä
10、千斤顶内有油压时，不得拆卸油管接头，防止高压射出伤人。n~F3…kabbs.3c3t.com÷h I±õ Ä
11、油泵电源必须接地避免触电。n~F3…kabbs.3c3t.com÷h I±õ Ä
12、要保持安全阀的灵敏可靠。n~F3…kabbs.3c3t.com÷h I±õ Ä
13、张拉时千斤顶后面严禁站人，张拉人员只能站在千斤顶两侧操作。n~F3…kabbs.3c3t.com÷h I±õ Ä
14、张拉完毕要注意保护，张拉完成后在三小时内不准进行下一道工序n~F3…kabbs.3c3t.com÷h I±õ Ä