《土力學(xué)》盧廷浩 主編 河海大學(xué)出版社

1、第一章土的物理性質(zhì)與工程分類1-1：有A、B兩個土樣，通過室內(nèi)試驗測得其粒徑與小于該粒徑的 土粒質(zhì)量如表所示，試?yán)L制出它們的粒徑分布曲線并求出c和c值。解：o o o o o o o2 0 8 6 4 21X 1x匕里含粒土的徑粒某于小0.1土粒粒徑d(mm)對 A 土樣：di0=0.085mm； d30=0. 38 mm； d60 = 0.96 mm,則c = d60 = 096 = 11.29u d 0.08510八（d 20.382C = 30 = 1.77對 B 土樣：di0=0.0012 mm；c d d 0.085 x 0.96d30 = 0.0028 mm； d60 = 0.00

2、5 mm ,則C = d60 = 0.005 = 4.17 u d 0.0012 10c =30c d d0.00282= 1 310.0012 x 0.0051-2從地下水位以下某粘土層中取出一土樣做試驗，測得其質(zhì)量為15.3g，烘干后質(zhì)量為10.6g，土粒比重為2.70。求試樣的含水量、孔 隙比、孔隙率、飽和密度、浮密度、干密度、及其相應(yīng)的重度。解：(1)已知：m= 15.3g, ms=10.6g, Gs=2.70, Sr=100%,則mw=m-ms=4.7gSr=100% IJ 47 = 4.7cm3 w p 1 w_ mG =ss Vp_ 10.6s = 3.93cm3G p 2.70

3、 x 1V=Vs+Vv=8.634.7(2) w = w x 100% =xm10.6100% = 44.3%4.7e =1.203.93s4.7- _ n = x 100% =x 100% = 54.5%8.63m 15.3 .一 _一 .8 63 = 1.77 g / cm3; y, = p, x g = 1.73kN / m3p =satp = p, - p = 0.77 g / cm3; y = px g = 7.5kN / m 3p = ms = 10.6 = 1.23 g / cm 3; y =p x g = 12.1kN / m 3d V 8.63d d1-3某土樣的含水率為6.

4、0%,密度為1.60g/cm3, 土粒比重為2.70,若設(shè)孔隙比不變，為使土樣飽和，問100cm3 土樣中應(yīng)加多少水?解：已知 w=6.0%, p =1.60g/cm3, Gs=2.70, ee V=100cm3m = p V = 160 gm 160m =s 1 + w 1 + 6.0%=150.94gm = m w = 9.06g150.94V = g = 270 1 = 55.90cm 3s wV = V - V = 44.10cm3所以，飽和時土中水總重為：m = Vp = 44.10 g需加入的水重為：Am = m - m = 44.10 - 9.06 = 35.04g1-4有土料1

5、000g，它的含水率為6%，若使它的含水率增加16%。問需加多少水?解：已知 m1=1000g, w1=6.0%, w2=16.0+6.0=22.0%. m1=ms+mw1=ms(1+w1). ms=m1/(1+w1)=1000/(1+6.0%)=943.40gmw1=msw1=943.40 X 6.0%=56.60gm2=ms(1+w2)=943.40 X (1+22.0%)=1150.95gmw2=m2-ms=1150.95-943.40=207.55g. Amw=mw2-mw1=207.55-56.60=150.95g 1-5有一砂土層，測得其天然密度為1.77g/cm3，天然含水率為9

6、.8%, 土粒比重為2.70，烘干后測得其最小孔隙比為0.46，最大孔隙比為0.94,試求出天然孔隙比、飽和含水率和相對密實度，并判別該砂土 層處于所種密實狀態(tài)？解：已知 p =1.77g/cm3, w=9.8%, Gs=2.70, emin=0.46, emax=0.94e =匕=V -1 =VVs-1.77二-1 =史5 -1 = 2.70 x(1 + 9) -1 = 0.67 m 1pWsatmwsatmsP,w匕 =w e = - x 0.67 = 24.8% p V p 2.70七二=0.94 頂7 =0.56 e - e .0.94 - 0.46.中密的。1-6解：已知 wA=15

7、%, GsA=2.75, SrA=50%;Wb=6%，Gsb=2.68, SrB=3%.p (1 + w) _ p (1 + w)1 + e 1 , wG1 +sS2.75 x (1 +15%),15% x 2.751 +50%=1.73g / cm32.68 x (1 + 6%) 6% x 2.681 +30%=1.85 g / cm3rp = m= d V wG1 +:Srp dA=1.51g / cm3 ； p = 1.74g / cm3wGe = 丁reA=0-825, eB=0.5361-8略。1-9某碾壓土壩的土石方為20萬方，設(shè)計填筑干密度為1.65g/cm3. 料場土的含水率為

8、12.0%,天然密度1.70g/cm3，液限為32.0%,塑限 為20.0%, 土粒比重為2.70。問：（1）為滿足填筑土壩需要，料場至少要多少方土料？（2）如每日填筑量為3000 m3,該土的最優(yōu)含水率為塑限的95%，為達(dá)到最佳碾壓效果，每天共需加水多少?（3） 土壩填筑后的飽和度是多少?解：已知 V=200000m3，p d=1.65g/cm3, w0=12.0%, p 0=1.70g/cm3,Wl=32.0%, wp=20.0%, GW.72。 p = % = m (1 + 叩=m0=4 = 4L = 1.52g/cm3d 0 V V (1 + W0) V (1 + W0)1 + W01 +12%vVp200000 x 1.65V =d = 217105.3m 30 p1.52d 0(2) w = w, x 0.95 = 20% x 0.95 = 19%m =