加筋擋土墻設(shè)計(jì)說(shuō)明

1、加筋土擋土墻設(shè)計(jì)說(shuō)明評(píng)語(yǔ):成績(jī):簽名:目錄第1章設(shè)計(jì)資料.1.第2章筋帶受力計(jì)算1.第3章內(nèi)部穩(wěn)定性驗(yàn)算 3.第4章外部穩(wěn)定驗(yàn)算 .5.加筋擋土墻設(shè)計(jì)說(shuō)明1. 結(jié)構(gòu)尺寸設(shè)計(jì)設(shè)計(jì)各項(xiàng)計(jì)算資料匯列如下：(1) 擋土墻不受浸水影響，墻高H=10m，頂部填土 0.6m，基礎(chǔ)埋深2m ；路基寬24.5m，路面寬18m ；(3)荷載標(biāo)準(zhǔn)：公路一級(jí)；面板規(guī)格：1.5m 0.8m，十字形混凝土板，板厚 20cm，混凝土強(qiáng)度等級(jí) C20。(5)筋帶采用聚丙烯土工帶，帶寬為18mm，厚2.0mm ,容許拉應(yīng)力二=50MPa，摩擦系數(shù) f=0.4；筋帶節(jié)點(diǎn)間距：Sx =0.42m,Sy =0.4m ；填料：砂性土，

2、重度 20kN/m3，內(nèi)摩擦角32，粘聚力c=0kPa ；(8) 地基：砂性土，重度 20kN/m3，內(nèi)摩擦角32，粘聚力c=0kPa，地基承載力標(biāo)準(zhǔn)值fa =600kPa ；(9) 墻體采用矩形斷面，加筋體寬為10.0m ；(10) 墻頂填料與加筋土填料相同，橫坡為6%,摩阻系數(shù)為亠=0.36 。2. 筋帶受力計(jì)算(1)計(jì)算加筋體上填土重力換算為等代均布土層厚度0 :已知H = 10m, a = 0.5m,m二1.5m, H0.6m，等代均布土層厚度計(jì)算如下：1H1h1( a)(5-0.5) = 3m H = 0.6m，故取 h = H = 0.6m。m21.5(2) 計(jì)算車(chē)輛荷載換算成等代

3、均布土層ho : 墻高 H _10m 時(shí)，q=10kN/m3。則 h0 二 q/孑=10/20 = 0.5m，ho=1.1m。(3) 筋帶受拉計(jì)算：筋帶受拉拉力包括三個(gè)部分：車(chē)輛荷載，墻頂路堤填土和墻后填料引起的筋帶拉力。中：靜止土壓力系數(shù)：k=1 -sin =1-sin32 =0.470 ；主動(dòng)土壓力系數(shù)：ka =tan2(45 _32 /2) =0.307 ；Hh當(dāng) h _ 6m 時(shí)，k = ko (1) ka ;當(dāng) h 6m 時(shí)，k = ka ； bc=0.9m。66加筋體我度孟處，附加豎直壓應(yīng)力勺的擴(kuò)散宣度-(ill).可按下式計(jì)算:Lci = G十久邑產(chǎn)+ H Lct = c + +

4、 Zj + H上 2AC)為=i h。二丁 =心(！ g 2 h2 ；爲(wèi))Sx SyLci筋帶編號(hào)hi(m)kiLci(m)Lc(m)(Tai(kpa)Y 1hi(kpa)Y 2h2(kpa)Sx(m)Sy(m)Ti(KN)10.20.4725.824.59.504220.420.42.8020.60.4526.2524.59.3312220.420.43.29310.4426.4524.59.2620220.420.43.7841.40.4326.6524.59.1928220.420.44.2451.80.4126.8524.59.1236220.420.44.6762.20.4027.0

5、524.59.0644220.420.45.0672.60.3927.2524.58.9952220.420.45.42830.3827.4524.58.9360220.420.45.7593.40.3627.6524.58.8668220.420.46.05103.80.3527.8524.58.8076220.420.46.31114.20.3428.0524.58.7384220.420.46.54124.60.3328.2524.58.6792220.420.46.731350.3128.4524.58.61100220.420.46.89145.40.3028.6524.58.551

6、08220.420.47.02155.80.2928.8524.58.49116220.420.47.12166.20.3129.0524.58.43124220.420.47.97176.60.3129.2524.58.38132220.420.48.371870.3129.4524.58.32140220.420.48.78197.40.3129.6524.58.26148220.420.49.19207.80.3129.8524.58.21156220.420.49.60218.20.3130.0524.58.15164220.420.410.01228.60.3130.2524.58.

7、10172220.420.410.422390.3130.4524.58.05180220.420.410.83249.40.3130.6524.57.99188220.420.411.24259.80.3130.8524.57.94196220.420.411.65拉筋容許應(yīng)力各層筋帶長(zhǎng)3. 內(nèi)部穩(wěn)定性驗(yàn)算 已知筋帶斷裂強(qiáng)度標(biāo)準(zhǔn)值fk =150MPa，抗拉容許應(yīng)力卜丨- 50MPa ,提高系數(shù)k =1，筋帶厚度為2mm利用容許應(yīng)力法計(jì)算結(jié)果見(jiàn)下表：筋帶編號(hào)Ti(KN)需要筋帶面積mm2選取根數(shù)安全系數(shù)12.8056.0031.9323.2965.8031.6433.7875.6052.384

8、4.2484.8052.1254.6793.4051.9365.06101.2051.7875.42108.4051.6685.75115.0051.5796.05121.0051.49106.31126.2051.43116.54130.8051.38126.73134.6051.34136.89137.8051.31147.02140.4051.28157.12142.4051.26167.97159.4071.58178.37167.4071.51188.78175.6071.44199.19183.8071.37209.60192.0071.312110.01200.2081.4422

9、10.42208.4081.382310.83216.60101.662411.24224.80101.602511.65233.00101.55(2)筋帶長(zhǎng)度計(jì)算計(jì)算各層筋帶在活動(dòng)區(qū)、錨固區(qū)的長(zhǎng)度及總長(zhǎng)。設(shè)計(jì)中加筋體為矩形斷面,度均為8m簡(jiǎn)化破裂面的垂直部分距面板背部的水平距離為：bH =0.3 H =3m32 簡(jiǎn)化破裂面下段高度：H2 =bH tan(45)=3 1.804 = 5.412m簡(jiǎn)化破裂面上段高度：H1 =:H 一日2 =10一5.412 =4.588m(3)抗拔穩(wěn)定性填料與筋帶間似摩阻系數(shù)取0.4，抗拔力調(diào)節(jié)系數(shù)查表得戎=1.4。筋帶長(zhǎng)度由公式Li二Lfi - Lai計(jì)算而得

10、?；顒?dòng)區(qū)的筋帶長(zhǎng)度可按下圖所示公式計(jì)算：Lfi = 0.3W(0 司 鳳)Lfi = H -知 tan 453 + #(Hl zf 10374.855B. 墻面的被動(dòng)土壓力Ep計(jì)算GN + %乙+昭-_232_路基底面C點(diǎn)處水平壓力Pc =20 2 tan2(45)=130.184kPa所以，Ep =0.5 130.184 2 =130.184kPaC. 各力對(duì)基底重心 O點(diǎn)的力矩Mg =G, h G2 l2 G3 l3 = -5.4 (4 -1.1) 145.2 (4.7 -4) 1600 0 =85.98kN mMa =374.855 (10 -6.366) = 1362.223kN m

11、M p -130.184 0.67 = 87.223kN m所以，M =Ma M p M g =1189.02kN mD. 基底合力偏心距及地基應(yīng)力計(jì)算_ M 1189.02 ccc LE0.68m1.33m1750.666e1750.60.636219.30kPa ： P =350kPa8886e1750.60.636218.35kPaL L88滿(mǎn)足要求。(2)基底滑移穩(wěn)定驗(yàn)算RnaxminN - _ N -L _ N】.1C 4加(號(hào)+&1朗時(shí)-加總ptanoj M 4 ( i, 1(； *%兮)畑口為加 *弊坨E廠(chǎng) Mana0式中：G一 用于皐底以上的重力(訕人 浸水擋七墻的浸水部分應(yīng)計(jì)

12、入浮力；耳墻踰主動(dòng)土壓力的輕向分fit (kN)；駄墻時(shí)主動(dòng)七壓力的水平分量(kN)；孫墻曲被動(dòng)土壓力的水平分雖(kN),當(dāng)為屁水掙土圾時(shí)* E嚴(yán)0;E；境前被動(dòng)土壓力水平分量的G3倍(kN);N柞用于基底上合力的豎向分力(kN).浸水擋丄墻應(yīng)計(jì)浸水部分的浮力; 偽莘底傾斜角基底為水平時(shí)*規(guī)范規(guī)定，當(dāng)荷載組合n時(shí)，要求的基底滑移穩(wěn)定系數(shù)K=1.3，取基底摩擦系數(shù)為 - 0.36 , Kc =上二=嚎1評(píng)二2.397 1.3，基底滑移穩(wěn)定性滿(mǎn)足要求。(3)傾覆穩(wěn)定性驗(yàn)算式中；乙；墻身重力.基礎(chǔ)重力、基礎(chǔ)上填土的墮力及作用于塔m的其他枸載的豎向 力含力覓心列縊趾的距離(rn)；兀墻后主動(dòng)土歩力的豎向分就到墻甜的斷離(rn)；Zv墻后主動(dòng)土壓力的忒平分塑到墟趾的距離(m) *心墻前被動(dòng)卜壓力的水平分倉(cāng)到墻趾的距離 5)。A. 各點(diǎn)對(duì)墻趾點(diǎn)的力矩計(jì)算Mg =5.4 1.1145.2 4.7 1600 4 =7088.38kN mMa =374.8