written 5.8 years ago by |
Pu=4105$\times10^{3}$N
For m20- CFL =20mpa
Step I.
Ap=$\frac{up}{0.6\ast fck}$
=$\frac{4105}{0.6\times 20}$
Ap=342.08$\times10^{3} mm^{2}$
Assume tg=16mm
$\neq$tf
$\gt $12.7mm
Safe
Assume ISA. 150$\times$ 115$\times$15 mm
2) width of plate(sp) =400+2(200)+2(16)+2(115)+2(24)
Bp=750mm
Lp$\frac{Ap}{Bp}=\frac{342.07\times 10^{3}}{750}$
Please=456.10
L=460mm
Step II
Thickness of base plate (tp)
Bmxx= at force of angle
By=$\frac{wl^{2}}{2}$. W=$\frac{our}{Ap}=\frac{4105\times 10^{3}}{750\times 460}$
=11.9mpa$\lt$0.6fck
=11.9$\lt$12 mpa. Hence safe
Bm =$\frac{11.9\times 124^{2}}{2}$. Ze$\frac{I}{y}$
=91.49$\times 10^{3}$N mm.
d =24+(115-15)
=124
But MD zo $\ast \frac{fry}{\gamma mo}$
=(s$\ast ze)\ast \frac{fy}{\gamma mo}....s=\frac{so}{Xe}$
Md=1.12$\ast(\frac{1\ast t^{t}}{6})\ast \frac{250}{1.1.}$
Step III
Bm@ circle $\frac{wll^{2}}{8}-\frac{wl^{2}}{2}$
$\frac{11.9\times 472^{2}}{8}-\frac{11.9\times 1.39^{2}}{2}$
BMC =216.43$\times10^{3}$Nmm—-3
BMC=216.43$\times20^{3}$Nmm
MD=zp$\ast \frac{fy}{\gamma mo}$
MD=(s$\ast ze) \ast\frac{fy}{\gamma mo}$
MD=1.12$\ast(\frac{1\times t^{2}}{6})\ast \frac{250}{1.1}$.....(4)
Equate equation 3&4
216.43$\times10^{3}=1.12+(\frac{1\times t^{2}}{7}\ast \frac{250}{1.1}$
t=71.23
t=72mm
But central portion has Bm in two direction t=$\frac{72}{2}$=36mm
Provide t=36mm
Provide base plate =460$\times750\times36$
Thickness of plate
Connection ( Bolted connection )
1) vdsb=$\frac{fub\times Anb\times nn}{\sqrt{3}\ast \gamma mb}$ assume 30mm dis of bolt
=>$\frac{400\times (0.78\times\frac{pi}{4}\times30^{2})\ast1}{\sqrt{3}\ast1.25}$
Vas’s=101.86$\times10^{3}$
Vdpb=2$\times kb\times d\times t \times fu$
=2$\times 0.5\times 30\times 15\times 410$
Vdpb=184.5$\times 10^{3}N$
Bolt value b=101.86 kN
No of bolts =$\frac{load/2}{Bolts / value}$=50x load directly vat 50% by connection
$\frac{4.105\times10^{3}/2}{101.86\times10^{3}}$ =20.15
Provide 24 bolts
No of bolts required to connect gusset with gusset angle will be same
Provide 24 bolts 30mm $\phi$ on each flange in two rows
Design of Anchor bolts
Holding down vbase plate by 6 nos30 mm$\phi$ at bolt of length 300 mm ( length x concrete Aedertal