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Vs,每立方米的土粒體積為: Vs = V/(1+e) = 1/(1+) = m3 Vv = eVs = = m3 當(dāng) Sr = 37%時(shí), Vw1 = SrVv = = m3 當(dāng) Sr = 90%時(shí), Vw2 = SrVv = = m3 則 ? Vw = – = m3 應(yīng)加水: ? Ww = ww W?? = 10 = 8m 厚的飽和粘土層,上下兩面均可排水,現(xiàn)從粘土層中心處取得 2cm 厚的試樣做固結(jié)試驗(yàn)(試樣上下均有透水石)。試樣在某級(jí)壓力下達(dá)到 60%的固結(jié)度需要 8 分鐘,則 該粘土層在同樣的固結(jié)壓力作用下達(dá)到 60%的固結(jié) 度需要多少時(shí)間?若該粘土層單面排水,所需時(shí)間為多少? 答:由于原位土層和試樣土的固結(jié)度相等,且 ? 值相等,因而 21 vv TT ? 又土的性質(zhì)相同, 21 vv CC ? 722222121222211 22??????????????????? HHttHtHt(如改單面,其達(dá)到 60%固結(jié)度時(shí)間為 3t 由 31 vv TT ? , 31 vv CC ? 則713213211 2???????????ttHtH t ( a)中給出地基中多層土中各土層的厚度、容重,繪制地基中的自重應(yīng)力隨深度的分布曲線(xiàn)圖。 [解] 由圖( a)給出的資料,可計(jì)算出各土層分界面上的應(yīng)力: k P ahsz 51)( ????? ?? k P ahszsz )(51239。212 ??????? ??? k P ahszsz )(39。323 ??????? ??? k P ahszsz )(39。434 ??????? ??? 上述自重應(yīng)力隨深度的變化關(guān)系結(jié)果 (b)。 ? 1 =? ? =? 2 =? 4 = (a)細(xì)砂粉質(zhì)粘土粘土 (b)??? ?? kN/m35 .033?? kN/m40 .038 .0 ???? kN/m 33341 .03?? kN/m 3344 .0 13. 已知地 基中一點(diǎn) 的大小主 應(yīng)力為 kPa3001 ?? ,kPa1503 ?? ,土的強(qiáng)度指標(biāo) kPac 20? , 16?? 176。,試判斷該點(diǎn)是否會(huì)剪破?剪破面與大主應(yīng)力之間的夾角為多少? 解:由摩爾 庫(kù)倫準(zhǔn)則: )245(2)245(231 ???? ???? ooff ctgtg =150 +2 20 = 由于:σ 1fσ 1=300kPa 或σ 3= 所以不會(huì)剪破。 某擋土墻高 8m,墻背豎直光滑,填土面水平,填土為無(wú)粘性土,γ =18kN/m3,φ =30176。,填土表面作用有連續(xù)均布荷載, q=20kPa。試用朗肯土壓力理論計(jì)算主動(dòng)土壓力以及作用點(diǎn)位置。 解 ( 1)土壓力系數(shù) 3123045tg245tgka 22 ??????? ?????????? ???? ( 2)主動(dòng)土壓力 墻頂 pa=qka=201/3= 墻底 pa=qka+rHka=+1881/3= 總土壓力 Pa=( +) /28=作用點(diǎn)距墻底的距離 ? ? 3y ????????? 在均布條形荷載作用下,土體中 A點(diǎn)的大主應(yīng)力σ 1=400kPa中,小主應(yīng)力σ 3=150kPa,土的抗剪強(qiáng)度指標(biāo) c=0,φ =30176。試求: 1) A點(diǎn)處土是否處于極限平衡狀態(tài)。 最危險(xiǎn)的剪應(yīng)力面與最大主應(yīng)面夾角為多少度? 解 : 1) k P a13322645tg0223045tg400245tgc2245tg2213??????? ???????????? ?????????? ??????????? ?????? 計(jì) 133kPa< 150kPa 處于穩(wěn)定狀態(tài) 2) 最危險(xiǎn)的剪應(yīng)力面與最大主應(yīng)面夾角 60176。 ( 10 分) 14. 有一條形基礎(chǔ),寬度 B 為 6m,埋深 D 為 ,其上作用著中心荷載 P 為 1700kN/m,地基土質(zhì)均勻,容重為19kN/m3,土的強(qiáng)度指標(biāo)為: c=20kPa, ? =20o,安全系數(shù)為,假定基底完全粗糙,應(yīng)用太沙基理論,驗(yàn)算地基的穩(wěn)定性 (? =20o 時(shí), ?rN , ?qN , 15?cN )。( 10 分) 解:( 1)基底壓力為: p=P/B=1700/6= (2) 由太沙基理論,地基的極限承載力為 cqru cNqNBNf ??? ?21 =19 6 +19 +20 15= (3) 容許承載力為 ? ? suFff ?=由于: p[f],地基不穩(wěn)定。 一、填空題 ( )、( )、( )三種類(lèi)型。 ( )、( )、( )。 ( )、( )、( )。 ( )、( )及( )。 ( )、( )與( )表示。 ( ),建筑物建造之后由荷載產(chǎn)生的應(yīng)力為( ),兩者之和是土中某一點(diǎn)的( )。 ( )、( )和( )三種。 8. 巖石(體)的力學(xué)性質(zhì)包括的巖石( )、( )、( )及巖石的破壞準(zhǔn)則。 ( )、( )和( )三種類(lèi)型。 ( )、( )、( )和巖土體失穩(wěn)四個(gè)方面。 二、選擇題 ( )方法。 、固結(jié)快剪和慢剪三種試驗(yàn)方法,一般情況下得到的內(nèi)摩擦角的大小順序是( )。 A. 慢剪 固結(jié)快剪 快剪 B. 快剪 固結(jié)快剪 慢剪 C. 固結(jié)快剪 快剪 慢剪 3. 在豎向集中力作用下,附加應(yīng)力說(shuō)法正確的是( )。 ,越向下越小。 B. 沿集中力作用處最大,越向下大。 C. 沿集中力作用處最小,越向下越 小。 D. 沿集中力作用處最小,越向下越大。 ,下列說(shuō)法正確的是( )。 。 B. 壓縮系數(shù)與壓縮模量成反比。 C. 壓縮系數(shù)越大,土的壓縮性越低。 D. 壓縮模量越小,土的壓縮性越低。 ( )。 A. f??? B. f??= C. f??? 三、問(wèn)答題 ? ? ? ,排水固結(jié)法有那幾種類(lèi)型? 四、計(jì)算題 ,試驗(yàn)測(cè)得容重 3cm/=? ,比重 G= ,含水量 %= ? 。 求:干容重,孔隙比,飽和度。 ,試計(jì)算地面下深度 z= 、 和 處土的自重應(yīng)力,并繪制自重應(yīng)力沿深度分布圖。 請(qǐng)您刪除一下內(nèi)容, O(∩ _∩ )O 謝謝!?。?2021 年中央電大期末復(fù)習(xí)考試小抄大全,電大期末考試必備小抄,電大考試必過(guò)小 抄 Basketball can make a true claim to being the only major sport that is an American invention. From high school to the professional level, basketball attracts a large following for live games as well as television coverage of events like the National Collegiate Athletic Association (NCAA) annual tournament and the National Basketball Association (NBA) and Women39。s National Basketball Association (WNBA) playoffs. And it has also made American heroes out of its player and coach legends like Michael Jordan, Larry Bird, Earvin Magic Johnson, Sheryl Swoopes, and other great players. At the heart of the game is the playing space and the equipment. The space is a rectangular, indoor court. The principal pieces of equipment are the two elevated baskets, one at each end (in the long direction) of the court, and the basketball itself. The ball is spherical in shape and is inflated. Basketballs range in size from in (7276 cm) in circumference, and in weight from 1822 oz (510624 g). For players below the high school level, a smaller ball is used, but the ball in men39。s games measures in (7576 cm) in circumference, and a women39。s ball is in (7274 cm) in circumference. The covering of the ball is leather, rubber, position, or synthetic, although leather covers only are dictated by rules for college play, unless the teams agree otherwise. Orange is the regulation color. At all levels of play, the home team provides the ball. Inflation of the ball is based on the height of the ball39。s bounce. Inside the covering or casing, a rubber bladder holds air. The ball must be inflated to a pressure sufficient to make it rebound to a height (measured to the top of the ball) of 4954 in ( m) when it is dropped on a solid wooden floor from a starting height of 6 ft ( m) measured from the bottom of the ball. The factory must test the balls, and the air pressure that makes the ball legal in keeping with the bounce test is stamped on the ball. During the intensity of high school and college tourneys and the professional playoffs, this inflated sphere mands considerable attention. Basketball is one of few sports with a known date of birth. On December 1, 1891, in Springfield, Massachusetts, James Naismith hung two half