深基坑手算計(jì)算書(shū)

1、20kPa ，荷處，第二道-11.5m處。土層相關(guān)參數(shù)見(jiàn)下表:表1 土層參數(shù)信息表土層編號(hào)土層名稱重度3(kN /m )黏聚力c(kPa)內(nèi)摩擦角()土層厚度(m)1-1雜填土160.7156.03-1-2新黃土 219.421.7224.03-2-2古土壤20.224.5204.84-1-2老黃土21.120.3246.1此基坑采用分層開(kāi)挖的方式，在基坑頂部承受擬定的均布荷載，荷載值為 載及各土層分布情況見(jiàn)圖q=20kPaT11 J 1 HT2 1-1雜填土T33-1-2 新黃土 23-2-2古土壤4-1-2老黃土圖1.1荷載分布及支護(hù)方案解:1計(jì)算各土層側(cè)壓力系數(shù)(1)工況1 :基坑開(kāi)挖至

2、-6.0m，并在此處設(shè)置第一道錨桿,地面處的主動(dòng)土壓力為:ea。 qKa12叭心120 0.589 2 0.7 0.767 10.706kPa6.0m處的主動(dòng)土壓力:第一層土層:$6 (qf1 zj Ka12g J Ka1Ka12tan (451/2)2tan (4515/2)0.589jKa10.767Ka2tan2 (452/2)tan2 (4522/2)0.455jKa20.675Ka3tan2 (453/2)tan2 (4520/2)0.490jKa30.700Ka4tan2 (454/2)tan2 (4524/2)0.422*40.649(2)郎肯被動(dòng)土壓力系數(shù)計(jì)算KP12tan (

3、451/2)2tan (4515 /2)1.6981.303Kp2tan2 (452/2)tan2 (4522/2)2.198pKp21.483KP3tan2 (453/2)tan 2(4520 /2)2.040Jkp31.428Kp4tan2 (454/2)tan2 (4524/2)2.371JKP41.540郎肯主動(dòng)土壓力系數(shù)計(jì)算(1)2各工況土壓力及支撐力計(jì)算(2016 6) 0.5892 0.7 0.76767.250kPa第二層土層:ea6 (q 1乙)心2 2c 7 Ka2(2016 6) 0.4552 21.70.67523.485k Pa開(kāi)挖面處的被動(dòng)土壓力為:ep6 2C2J

4、KP22 21.7 1.48364.362k Pa開(kāi)挖面處主動(dòng)土壓力減去被動(dòng)土壓力為:e6 ea6 ep6 23.485 64.36240.877k Pa233.868kN /m則所有的主動(dòng)土壓力合力為:Ea1 0.5 (10.706 67.250) 610.70640.877p"1I67.250t1et13.2工況1 土壓力分布圖圖假設(shè)開(kāi)挖面以下t1m處剪力為0，該處即是最大彎矩所在截面， 則t1m處的主動(dòng)土壓力減去被動(dòng)土壓力為:e1 e62t1 Ka2 ( 2t1K P22C2JK P2)23.485 19.41 0.455 (19.4t1 2.198 2 21.7 1.483)

5、 (33.814t140.877)kPa由靜力平衡列方程:Eai 0.5 (40.87740.87733.814ti)ti233.86840.877t116.592*解得 t12.719m所以 et133.814 2.719 40.877132.817kPa因此最大彎矩為:M max1 10.706 6 (0.540.877 2.719 0.5 2.719 0.56 2.719) 0.5 (67.250 10.706) 6 (% 6 2.719) (132.817 40.877) 2.719 % 2.719827.266kN m/m工況2 :開(kāi)挖至處11.5m，并在此處設(shè)第二道錨桿，土壓力分布

6、:ea11.53d2Ka3ep11.53 d2 KP3開(kāi)挖面處主動(dòng)土壓力:第二層土層:ea10ea62z2Ka223.48519.4 4 0.45558.793k Pa第三層土層:ea10(q1乙2Z2)Ka3 2c3jKa3(2016 6 19.4 4) 0.4902 24.5 0.70060.564kPa開(kāi)挖面處的主動(dòng)土壓力為:ea11.5ea103z2Ka3 60.564 20.2 1.5 0.490 75.411kPa開(kāi)挖面處的被動(dòng)土壓力為:ep11.5 2cKp32 24.5 1.428 69.972kPa則主動(dòng)土壓力減去被動(dòng)土壓力為:e,1.5 ea11.5 ep11.575.41

7、1 69.972 5.439kPa假設(shè)土壓力零點(diǎn)位置為開(kāi)挖面以下d2處，則有:d2ei1.55.4393(Kp3 Ka3)20.2 (2.040 0.490)0.174m主動(dòng)土壓力合力為:Ea2233.8680.5 (23.485 58.793) 4 0.5 (75.41160.564) 1.5500.878kN / m土壓力零點(diǎn)位置處截面的彎矩為:Ma210.706 6(0.5 641.50.174)0.5 (67.250 10.706) 6 (%64 1.5 0.174)23.4854(0.54 1.50.174) 0.5 (58.793 23.485)4(% 4 1.5 0.174) 6

8、0.564 1.5 (0.5 1.5 0.174) 0.5 (75.411 60.564)1.5 (% 1.5 0.174) 0.5 5.439 0.174 % 0.174 2507.943kN m/m則第一道(6m)處錨桿的水平分力為:T1 Ma22507442.006kN/ma25.5 0.174假設(shè)土壓力零點(diǎn)位置以下t2m處剪力為0,即彎矩最大，則由幾何關(guān)系可知，t2m處的土壓力為:5.439t20.174et2et231.259t2由靜力平衡可列方程:T1丁10.706'、23.48567.25058.79360.5645.43975.411d2et2t2M max2(% 61

9、0.706 6 (0.54 1.5 0.1746 4 4.5 0.1741.941)0.5 (67.250 10.706) 6(58.7931.941)23.485 423.485) 4 (% 4 1.5 0.174(0.5 41.5 0.174 1.941)0.51.941)60.564 1.5(0.5 1.5 0.1740.5 (75.411 60.564) 1.5 (%1.941)(% 0.174 1.941)0.5 1.941 60.6741.941)270.607kN m/m1.5 0.174% 1.9411.941)442.0060.5 5.439 0.174(5.5 0.174工

10、況3:開(kāi)挖至 17.0m，并在此處設(shè)第三道錨桿:ea14.8ea103z3Ka360.564 20.2 4.8 0.490108.074k Pa第四層土層:ea14.8(q1Z12 Z2I3Z3 ) Ka4 2C4 寸 Ka4圖3.3工況2 土壓力分布圖Ea2 T10.5 et2t2500.878442.0060.531.259t2 t2解得t21.941m所以et231.259 1.94160.674 k Pa因此最大彎矩為:(20 16 6 19.4 4 20.2 4.2) 0.4222 20.3 0.64996.267k Paea17 ea14.54z4Ka4 96.26720.2 2.

11、2 0.422 115.856k Pa開(kāi)挖面處的被動(dòng)土壓力為:epi7 2C4JKP42 20.3 1.540 62.524kpa主動(dòng)土壓力減去被動(dòng)土壓力:e17 ea17 ep 115.856 62.524 53.332kPa假設(shè)土壓力零點(diǎn)位置為開(kāi)挖面以下d3處，則:10.706Ti23.48567.250' 58.793T260.564108.07496.26753.332115.856d3t3et?圖3.4工況3的土壓力分布圖115856 21.1 d3 0.422 21.1 ds 2371 2 20.3 1.540ea174dKa44dKp4 2C4JK p4解得 d 1.29

12、7m所有主動(dòng)土壓力合力為:Ea3 0.5 (10.706 67.250) 60.5 (23.485 58.796) 4 0.5 (60.564108.074)4.8 0.5 (96.267 115.856) 2.2 0.5 53.332 1.2971070.076kN/m土壓力零點(diǎn)處截面的彎矩為:Ma310.706 6(0.5 6 44.82.51.297)0.5 (67.250 10.706)6(% 6 4 4.8 2.2 1.297) 23.485 4 (0.5 4 4.8 2.2 1.297) 0.5 (58.793 23.485)4 (% 44.82.21.297)60.564 4.8

13、 (0.5 4.8 2.21.297) 0.5 (108.074 60.564) 4.8 (% 4.8 2.2 1.297) 96.267 2.2(0.5 2.2 1.297) 0.5 (115.856 96.267) 2.2 (% 2.2 1.297) 0.5 53.332 1.297 % 1.2977931.991kN m/mMa3 T1 (176)T2所以第二道（11.5m處）錨桿的水平分力為:5.5 1.2977931.991442.006 (111.297)5.5 1.297438.303kN/m假設(shè)土壓力零點(diǎn)位置以下 t3m處剪力為0,即該處彎矩最大，則該界面處的土壓力為:由幾何關(guān)

14、系有:et3t353 .332d31070.076442.006438.303 0.5 41.120t3 t3所以 ©341.120t3則由靜力平衡列方程:Ea3 Ti T20.5 41.120 t? t?解得 t33.038met341.120 3.038124.922kPa因此最大彎矩為:Mmax3 10.706 6 (0.5 6 4 4.8 2.2 1.297 3.038) 0.5 (67.250 10.706)6 (% 6 4 4.8 2.2 1.297 3.038) 23.485 4 (0.5 4 4.8 2.2 1.2973.038)0.5 (58.793 23.485)

15、 4 (% 44.8 2.2 1.2973.038)60.564 4.8(0.5 4.8 2.2 1.297 3.038)0.5 (108.074 60.564) 4.8 (% 4.8 2.2 1.21.297 3.038)438.303 (11 5.5 1.2973.038)97 3.038) 96.267 2.2 (0.5 2.2 1.297 3.038) 0.5 (115.856 96.267) 2.2 (% 2.2 1.297 3.038) 0.5 53.332 1.297 (% 1.297 3.038) 0.5 124.922 3.038 % 3.038 442.006 (1195.

16、109kN m/m(4 )嵌固深度的計(jì)算TdEa3 T1 T2 1070.076442.006 438.303 189.767kN/meh 41.120h圖3.5嵌固深度計(jì)算圖對(duì)O點(diǎn)取矩，由力矩平衡可知:M (O)0 :189.767 h 0.5 (41.120h) h % h 0解得 h 5.262m則嵌固深度ha 1.2(h t3)1.2 (5.262 3.038)9.96m因此樁總長(zhǎng)L 17 9.9626.96m3灌注樁的內(nèi)力設(shè)計(jì)值及配筋設(shè)計(jì)最大彎矩計(jì)算值:Mc 827.2661.51240.899kN m最大彎矩設(shè)計(jì)值：M 1.25 0Mc1.251.1 1240.899 1706.2

17、36kN m灌注樁的配筋取分段開(kāi)挖的最大彎矩:max 1240.899kN m。彎矩設(shè)計(jì)值為： M 1.25 1.1 1240.899 2047.0kN m查基坑工程手冊(cè)附表14-4選用28 25，截面容許彎矩設(shè)計(jì)值M 2068.0kN m 2047.0kN m，樁體選用C30混凝土，箍筋選用10150螺旋筋,加強(qiáng)筋 202000。4錨桿計(jì)算錨桿傾角20。，水平間距2m，鉆孔直徑0.15m。錨索采用175預(yù)應(yīng)力鍍鋅鋼絞線,強(qiáng)度標(biāo)準(zhǔn)值fptk 1470N/mm2。根據(jù)土體與錨固體極限摩阻力標(biāo)準(zhǔn)值表，可知新黃土的極限摩阻力取70kPa，古土壤的極限摩阻力取73kPa，老黃土的極限摩阻力取68kPa，各層加權(quán)內(nèi)摩擦角為 20 0。水平力設(shè)計(jì)值:Td2T2438.303 2876.606kNTdi 1.25 oTi 1.25 1.1 884.012 1215.517kN1.25 0T21.25 1.1 876.606 1205.333kN錨桿設(shè)計(jì)的軸向拉力為:Nu1=1215.517/cos20 o=1292.55 kNNu2=1205.333/cos20o=1281.91 kN錨桿的錨固長(zhǎng)度lala1km