基础工程课程设计(桩基础设计)

1、*大学土木工程学院基础工程课程设计(土木工程地下工程方向姓名:*学号:*组别:*一班(ACE组二一一年六月目录一. 工程概况 (3二 .选择桩型、桩端持力层、承台埋深 (6三. 确定单桩承载力特征值 (6四. 确定桩数 (7五. Z1、Z2类柱下桩基础设计 (8六. Z3类柱下桩基础设计 (11七. Z4类柱下桩基础设计 (14八. 连系梁设计 (18九. 基础布置总平面图 (20一 .工程概况凤凰大厦为六层框架结构,±0.00以上高度19.6米,拟采用400×400mm 2钢筋混凝土预制桩基础,整个基础占地面积为(22.8350.322.780.6m =+.具体的地质等工

2、程条件如下:Z 1Z 2Z 2Z 2Z 2Z 2Z 2Z 2Z 1Z 1Z 2Z 2Z 2Z 2Z 2Z 2Z 2Z 1 Z 3Z 3Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 4Z 3Z 3123456789DCB A底层柱网平面布置图1、场地工程地质条件 (1钻孔平面布置图17.5m 16.0m 16.0m 16.0mZk5Zk6Zk7Zk8Zk1Zk2Zk3Zk4(2工程地质剖面图-1.8-2.0-2.2-2.5-5.1(-5.8 -9.5(-10.5 -18.4(-20.4-3.0(-4.0-15.5(-17.3-4.5(-5.3-8.6(-9.2

3、-20.5(-21.8-6.0(-6.5-9.0(-9.7-20(-21.2杂填土淤泥粉质粘土砾质粘土-8.5(-9.8剖面-1.8-2.0-2.2-2.4-4.9(-4.5 -10.0(-11.4 -14.5(-16.3-3.0(-4.5-8.0(-9.4-17.0(-18.5-5.5(-6.2-22.0(-23.0-6.5(-7.5-9.5(-11.3-21.5-(22.0杂填土淤泥粉质粘土砾质粘土-8.5(-10.7剖面(3预制桩桩端承载能力标准值土层名称桩周侧摩阻力标准值q sk(kPa桩端极限承载力标准值q sk(kPa杂填土未完成自重固结/淤泥10 /粉质粘土40 1900砾质粘土

4、50 35002、底层柱截面尺寸及荷载底层柱柱截面尺寸轴力(KN偏心距离Z1400×400 1050 0.2Z2400×400 1280 0.2Z3400×600 1900 0.2Z4500×700 2000 0.13、其它条件(1柱底标高为-1.0m;(2基础梁(连系梁顶面荷载Q=15kN/m;(3建筑物处于非地震区,可不考虑抗震。二 .选择桩型、桩端持力层 、承台埋深根据荷载和地质条件,以砾质粘土层做为桩端持力层。四类柱下桩统一选用同一种桩型,采用桩截面为400mm ×400mm 钢筋混凝土预制桩,桩长21.9m ,桩入土深度为23.8m

5、。承台埋深2m 。厚度为1.0m 。三.确定单桩承载力特征值-剖面 (KN h q u A q R n i n i i sia p p pa a 816504.5409.8104.46.116.035001211211=+=+= (KN h q u A q R n i ni i sia p p pa a 880503.8407105.56.116.035001211212=+=+=(KN h q u A q R n i ni i sia p p pa a 808508.340111036.116.035001211214=+=+=1K Z 2K Z 3K Z (KN h q u A q R n

6、 i n i i sia p p pa a 6.825503.3409.11101.46.116.035001211213=+=+=4K Z-剖面四.确定桩数最安全设计时取R a =780KN,根据柱的顶面荷载大小确定桩数:Z 1 62.178010502.12.11=a R F n 取两根桩 Z 2 97.178012802.12.12=a R F n 取两根桩 Z 3 92.278019002.12.13=a R F n 取三根桩 Z 4 08.378020002.12.14=a R F n 取三根桩 5K Z (KN h q u A q R n i n i i sia p p pa a

7、8.836503.9405.4101.56.116.035001211215=+=+=(KN h q u A q R n i n i i sia p p pa a 880508.64091056.116.035001211216=+=+=6K Z 7K Z (KN h q u A q R n i ni i sia p p pa a 808508.1405.131036.116.035001211217=+=+=8K Z (KN h q u A q R n i n i i sia p p pa a 780503.240121036.116.035001211218=+=+=五.Z 1、Z 2类柱

8、下桩基础设计(Z 1、Z 2类柱承台选用同一种类型,因Z 2柱上竖向力大于Z 1柱上的竖向力.故参照Z 2类柱的相关数据来进行此类基础的设计 (一选用两根桩,桩长21.9m,即入土深度23.8m.嵌入承台的0.1m.(二单桩承载力(最保守设计计算时R a =780KN(三单桩承载力验算初选承台厚度1.0m,埋深2.0m,承台初选2.0m ×10.m.面积A=2.0m 2KN Ad G G 802220=KN R KN n G F Q a K 7806802801280=+=+= KN R KN x x M n G F Q a ji y k 9362.13.8936.026.02.01

9、280280128022max ,=+=+= (四.配筋KN F F k 1728128035.135.1=m KN M M k =6.3452.0128035.135.1各桩不计承台自重及其上土重GK 时净反力:KN nF N k i 86435.1= 最大竖向力:KN x x M n F N j y k 129635.12max max =+= 对于最承台危险截面:m KN x N M i i y =4.5184.01296 承台选用C30的混凝土:F t =1.143N/mm 2钢筋选用HRB335级的钢筋:F y =300N/mm 2桩顶嵌入承台100mm.则有效厚度:mm 89010

10、10010002-100-h h0=-=26035.21338903009.0104.5189.0mm h f M A y yS = 最小配筋率:%215.0%30043.145%45min =y t f f 2min 21.19098901000%215.035.2133mm bh mm A s =>=满足最小配筋率要求.选用812和814钢筋s A =8×113.0+8×153.9=2135.2mm 2 (五. 抗冲切验算1.承台上柱的抗冲切验算4.0=c a 4.0=c b 0.1=hp 14.12.048.022.09.02.02.00=+=ox ox ox

11、ox ox h a m a 2.42.084.0000=+=oy oy xoy oy h a a (o t hp ox c oy oy c ox l h f a a a b F +KN6.378789.014300.12.04.0(2.404.0(14.1=+=KN N F F l 172801728=-=-=故承台柱的冲切满足设计要求.2.角桩的冲切验算m c 6.01= c 7.02=33.12.056.022.09.02.02.0110111=+=x x xx x h aa 8.22.056.000110111=+=x x xx y h aa o t hp x y y x l hf a

12、c ac N + +22111121(KN N N KN L 12964.367989.014300.11.06.08.207.033.1max =+ 角桩验算满足要求1c xa12c(六.承台抗剪验算0h b f V t hs 对于-截面2.0=x a 22.00=h a x x 取25.0=x 4.1175.1=+= 97.0800410= =h hs KN N V KN 12964.172889.097.014304.11max =承台抗剪符合设计要求六.Z 3类柱下桩基础设计 (一.选用三根桩,桩长21.9m,即入土深度23.8m.嵌入承台的厚度0.1m(二.单桩承载力(最保守设计计算

13、时R a =780KN(三.单桩承载力验算选承台厚度1.0m,埋深2.0m,桩中心距Sa=2.0m,承台面积A=5.68m 2KN Ad G G 2.227268.520= KN R KN n G F Q a K 7801.70932.2271900=+=+= 0.2155.1577.02222=+=i yKN R KN y y M n G F N N N a j i x 9362.17.8182577.02.0190032.2271900232max =+=+=KN y y M n G F N N ji x 7.4892155.12.0190032.227190021min =-+=-+=

14、xa(四.配筋 (承台按三向板带均匀布置KN F F k 2565190035.135.1=m KN M M k =5132.0190035.135.1各桩不计承台自重及其上土重GK 时净反力,KN nF N k i 85535.1= 最大竖向力:KN x x M n F N j y k 10032577.02.019003190035.135.12max max =+=+= m KN b S N M c a = -= -=8.6104.0432*max 承台选用C30的混凝土,F t =1.43N/mm 2;钢筋选用HRB335级钢筋F y =300N/mm 2桩顶嵌入承台100mm.则有效

15、厚度:mm 8901010010002-100-h h0=-=2608.25418903009.0108.6109.0mm h f M A y y S = 最小配筋率:%215.0%30043.145%45min =y t f f 2min 21.1833890958%215.08.2541mm bh mm A s =>=, 所以满足最小配率要求. 三角承台的每一边选用1416钢筋s A =14×200.96=2813.4mm 2(五.承台抗冲切验算1.柱对承台的冲切验算00h f u F t m hp l 992.08902000(800200089.0189.0=-+=hp

16、 mm a 6550= mm 266825336= 74.089065500=h a 894.02.007484.02.084.00=+=+= KN F KN h f u l t m hp 10033.301189.01043.1668.2894.0992.0300= 柱的冲切满足设计要求.2.角桩对承台的冲切验算mm c 10661= mm c 10392= 97.0800410= =h hs mm a 60011= 67.090060001111=h a 64.02.056.01111=+= mm a 56712= 63.090056701212=h a 67.02.056.01212=+

17、= .底部角桩(01111112tan 2h f a c N t hp l +(KN 124689.0143097.0260tan 6.0066.1264.00=+= KN x x M n F N N j y k l 10032577.02.019003190035.135.12max max 0=+=+= .顶部角桩(02122122tan 2h f a c N t hp l +(KN 5.126489.0143097.0260tan 567.0039.1267.00=+=KN x x M n F N N j y k l 7.5582155.12.019003190035.135.12max

18、 10=-=-= 所以底部和顶部角桩冲切均符合设计要求 (六.承台抗剪验算0h b f V t hs 对于-截面6.0=x a 67.00=h a x x 05.1175.1=+= 97.0800410= =h hs KN N V KN 10035.239189.0845.1143005.197.0max = 对于-截面655.0=x a 728.00=h a x x 01.1175.1=+= 97.0800410= =h hs KN N V KN 7.5582.172889.0386.1143001.197.010= 承台抗剪符合设计要求.七.Z 4类柱下桩基础设计(一.选用三根桩,桩长21

19、.9m,即入土深度23.8m.嵌入承台的厚度0.1m(二.单桩承载力(最保守设计计算时R a =780KN(三.单桩承载力验算选承台厚度1.0m,埋深2.0m,桩中心距Sa=2.0m,承台面积A=5.68mm 2KN Ad G G 2.227268.520=KN R KN n G F Q a K 7804.74232.2272000=+=+= 0.2155.1577.02222=+=i yKN R KN y y M n G F N N a j i x 9362.11.8002577.01.0200032.2272000232=+=+=KN y y M n G F N ji x 9.626215

20、5.11.0200032.227200021=-+=-+= (四.配筋 (承台按三向板带三向布置KN F F k 2700200035.135.1=m KN M M k =2701.0200035.135.1各桩不计承台自重及其上土重GK 时净反力,KN nF N k i 90035.1= 最大竖向力 KN x x M n F N j y k 9.9772577.01.020*.135.12max max =+=+= m KN b S N M c a = -= -=4.5815.043239.977433max 承台选用C30的混凝土,F t =1.43N/mm 2钢筋选用HRB335级钢筋F

21、 y =300N/mm 22605.24198903009.0104.5819.0mm h f M A y yS = 最小配筋率:%215.0%30043.145%45min =y t f f 2min 21.1833890958%215.05.2419mm bh mm A s =>=, 所以满足最小配率要求. 选用1416钢筋s A =14×200.96=2813.4mm 2 (五. 承台抗冲切验算 1.柱对承台的冲切验算00h f u F t m hp l 992.08902000(800200089.0189.0=-+=hp mm a 6050=mm 266825336=

22、 68.0890605=h a 95.02.068.084.02.084.00=+=+= KN F KN h f u l t m hp 10030.314089.01043.1668.295.0992.0300=柱的冲切满足设计要求. 2.角桩对承台的冲切验算mm c 10661= mm c 10392= 97.0800410=h hs mm a 55011= 61.090055001111=h a 69.02.056.01111=+=mm a 52412= 58.090052401212=h a 72.02.056.01212=+=底部角桩(01111112tan2h f a c N t h

23、p l +(KN 0.131989.0143097.0260tan 55.0066.1269.00=+KN N N l 9.977max 0=顶部角桩(02122122tan2h f a c N t hp l +(KN 6.13519.0143097.0260tan 524.0039.1272.00=+KN N N l 3.8469.62635.110=所以底部和顶部角桩冲切均符合设计要求 (六承台抗剪验算0h b f V t hs 对于-截面55.0=x a 61.00=h a xx 09.1175.1=+= 97.0800410= =h hs KN N V KN 9.9776.248289

24、.0845.1143009.197.0max 0= 对于-截面605.0=x a 67.00=h a xx 05.1175.1=+= 97.0800410= =h hs KN N V KN 3.8466.179689.0386.1143005.197.010=抗剪符合设计要求. 八.连系梁的设计已知梁上的荷载为15KN/m.所有的连系梁选用同一种类型的混凝土材料(C30:f t =1.43N/mm 2,f c =14.5N/mm 2,同种型号钢筋(HRB335:f y =300N/mm 2.由桩基础设计手册中查得:连系梁顶面宜与顶面位于同一标高,其宽度不宜小于250mm,其高度可取承台中心距的

25、1/101/15,但不超过承台的高度,且不宜小于400mm.据此对以下四类梁进行设计.(一类. Z1-Z2和Z2-Z2之间连续梁设计此类梁在两承台间的距离为4000mm,两端各嵌入承台50mm.则梁的总长为:L=4100mm.梁高度取h=500mm.宽度取300mm.则:mm a h h s 465355000=-=-=033.04653005.1411005.205.2152122201=bh f a M c s 55.0034.0033.0211211=-=-=b s a 2102.2293005.141465300052.0mm f f a bh A y c s = 选用412 22.452