钢筋混凝土柱基础设计



				钢筋混凝土柱基础设计
条件:	1	地面以下:	d=	2	m
	2	柱脚:	1000X1000
		混凝土:	C20
	3	荷载:	N=	1847.40	kN
			MX=	777.43	kN.M
			VX=	113.39	kN
	4	基础埋深:	d+h=	3.00	m
	5	地基承载力标准值:fk=		300	kPa
	6	基底保护层:		50	mm
有关参数:	h1=	0		h2=	0
	g1=	18	kN/m3	g2=	20	kN/m3
	ft=	1.1	N/mm2	fc=	10	N/mm2
	一级钢筋 fy=	210	N/mm2
	二级钢筋 fy=	310	N/mm2
基础设计:	a=	1000	mm	b=	1000	mm	h=	1000	mm
	a1=	600	mm	b1=	600	mm	h1=	400	mm
	a2=	500	mm	b2=	500	mm	h2=	300	mm
	a3=	400	mm	b3=	400	mm	h3=	300	mm
	L=	4000	mm	B=	4000	mm
	A=	L * B =	16	m2
	Wx=	L * B2 / 6    =		10.667	m3
	Mx=	V * h	+	M
	=	113.4	+	777.4
	=	890.8	kN.m
	f=	fk  +	h1 * g1   (	B - 3 ) +	h2 * g2   (	d - 0.5 )
	=	300.0	+	0	+	0
	=	300.0	kPa <	1.1fk=	330	kPa
	则：  f=	330.0	kPa
基底压力验算:
	G=	g2 * A *	(d +h)  =	960.00	kN
	e=	Mx / ( N +G )   =		317	mm  <	B / 6 =	667	mm
	且:	B - 3( B/2 - e )  =		0	mm  <	B / 4 =	1000	mm
								OK!
	Ps=	(N+G) / A	=	175.46	kPa  <	f=	330	kPa
	Psmax=	(N+G) / A + Mx / Wx    =			258.98	kPa  <	1.2 f =	396	kPa
	Psmin=	(N+G) / A - Mx / Wx    =			91.95	kPa		OK!
冲切验算:
	H01=	h01=	350	mm
	AL1=	(b1 - H01) * [b1 + H01 +(a+2a2+2a3)]
	=	0.9375	m2
	FL1=	Psmax * AL1   =		242.8	kN
	am1=	a + a2 + a3 + H01 =		2250	mm
		FL1 / ( 0.6 ft * am1 ) =	163	mm  <	H01	OK!
	H02=	h01 + h2=	650	mm
	AL2=	[(b1+b2) - H02] * [(b1+b2) + H02 +(a+2a3) ]
	=	1.5975	m2
	FL2=	Psmax * AL2   =		413.7	kN
	am2=	a + a3 + H02 =		2050	mm
		FL2 / ( 0.6 ft * am2 ) =	306	mm  <	H02	OK!
	H03=	h0=	950	mm
	AL3=	[(b1+b2+b3) - H03] * [(b1+b2+b3) + H03 +a ]
	=	1.8975	m2
	FL2=	Psmax * AL3   =		491.4	kN
	am3=	a + h03 =	1950	mm
		FL3 / ( 0.6 ft * am3 ) =	382	mm  <	H03	OK!
剪切验算:
	V=	(Pnmax+Ps1)*(b1-h01)*b/2=			246.45	kN
		0.07fcbh01=	980	kN
	V<	0.07fcbh01	OK!
板底配筋:
X:	Ps1=	233.92	kPa
	Ps2=	213.04	kPa
	Ps3=	196.34	kPa
	M1-1=	[( Psmax + Ps1 - 2G/A ) / 2]    *			b12	*	(3L - 2a1) / 6
	=	186.45	*	0.360	*	1.800
	=	120.82	kN.m
	M2-2=	[( Psmax + Ps2 - 2G/A ) / 2]    *			(b1+b2)2	*	[3L - 2(a1+a2)] / 6
	=	176.01	*	1.210	*	1.633
	=	347.86	kN.m
	M3-3=	[( Psmax + Ps3 - 2G/A ) / 2]    *			(b1+b2+b3)2	*	[3L - 2(a1+a2+a3)] / 6
	=	167.66	*	2.250	*	1.500
	=	565.85	kN.m
	As1-1=	M1-1 / ( 0.9h01 * fy )  =		1826	mm2  (一级钢筋)  or		1237	mm2  (二级钢筋)
	As2-2=	M2-2 / ( 0.9h02 * fy )  =		2832	mm2		1918	mm2
	As3-3=	M3-3 / ( 0.9h03 * fy )  =		3151	mm2		2135	mm2
		Asmax	=	788	mm2/m		534	mm2/m
		As实际	=	565	mm2/m	二级钢筋 12@200