外文翻譯---飽和全風(fēng)化火山巖填土穩(wěn)定狀態(tài)的三軸壓縮試驗(yàn)

1、<p><b>　　附錄A 譯文</b></p><p>　　飽和全風(fēng)化火山巖填土穩(wěn)定狀態(tài)的三軸壓縮試驗(yàn)</p><p>　　翟 陽(yáng)1，李焯芬2，羅錦添3</p><p>　　(1.煙臺(tái)大學(xué)基建處, 山東煙臺(tái)264005；2.香港大學(xué)土木工程系, 香港薄扶林；</p><p>　　3.加拿大Carleton大學(xué)

2、土木及環(huán)境工程系, 渥太華K1S 5B6)</p><p>　　摘要：在重塑試樣的三軸壓縮實(shí)驗(yàn)基礎(chǔ)上，對(duì)全風(fēng)化火山巖松散填土的穩(wěn)定狀態(tài)進(jìn)行了分析研究。 探討了試樣的相對(duì)壓實(shí)度、初始含水量、應(yīng)變速率對(duì)穩(wěn)定狀態(tài)的影響。 得出了穩(wěn)定狀態(tài)線在平面內(nèi)不唯一的結(jié)論，其位置隨上述因素變化。提出了一種歸一化方法，在考慮相對(duì)壓實(shí)度、初始含水量效應(yīng)的情況下可以給出單一的穩(wěn)定狀態(tài)線。</p><p>　　關(guān)鍵詞

3、: 全風(fēng)化火山巖；松散填土；穩(wěn)定狀態(tài)</p><p>　　在香港，完全分解的火山(CDV)殘余土壤用于道路并且暫時(shí)代替斜坡的主要填充材料之一。在20世紀(jì)70年代之前，很多填充斜坡通常是沒有緊密壓縮建成的。在20世紀(jì)70年代內(nèi)，兩個(gè)發(fā)生傾斜滑坡的災(zāi)難性填充是在20世紀(jì)60年代內(nèi)建造的。這樣的滑落是由靜止的液化的引起的[1 , 2 ]。由于仍然有地區(qū)存在這種很多松散的填充斜率，為了改進(jìn)和補(bǔ)救工作，有良好的CDV 松散

4、填充靜止的液化行為知識(shí)是重要的。穩(wěn)態(tài)行為是這篇文章的關(guān)鍵要素之一。這篇論文的目的是調(diào)查松散的填充，通過(guò)一系列三軸壓縮測(cè)試CDV的穩(wěn)態(tài)行為。</p><p>　　在靜態(tài)液化和土壤倒塌行為的分析中穩(wěn)態(tài)是一個(gè)非常重要的概念。它可以在空間中通過(guò)一條直線來(lái)描述或者在和中顯示。其中，和。獨(dú)一無(wú)二的穩(wěn)態(tài)線是很有爭(zhēng)議的。一些研究[3 , 4 ]顯示這條穩(wěn)態(tài)行是獨(dú)特的。另一方面，一些研究顯示這條穩(wěn)態(tài)行不獨(dú)特并且取決于因素(例如：干

5、燥密度，壓力路徑，最初限制的壓力，應(yīng)變控制，載荷控制試驗(yàn)等等)。這些研究包括由Yamamuro 和Lade[5 ]，Vaidetal[6 ]，Riemer和Seed [7 ]，康拉德[8 ]，赫德和Hassona[9 ]等等所作的工作。全部研究在圖上顯示唯一穩(wěn)態(tài)線，但是在圖上這條穩(wěn)態(tài)線好像隨許多因素而變化。</p><p><b>　　1 試驗(yàn)方案</b></p><p&

6、gt;　　本試驗(yàn)中的土壤取自香港新領(lǐng)土的大網(wǎng)仔道路。它是一種完全分解火山殘余的土壤。最佳含水量是百分之三十一，最大的干燥密度是1. 36Mg/ m3，粒子密度是2. 68Mg/ m3和粘土含量是百分之四十一。</p><p>　　試樣由這種潮濕的填充方法形成，并且尺寸的高度是152毫米和直徑是76毫米。樣品是在一定含水量五個(gè)層緊密結(jié)合的。在最初密度被選擇之后，總重被計(jì)算，每個(gè)層對(duì)相同的厚度有相同數(shù)量的土壤完全緊密

7、結(jié)合。試驗(yàn)飽和是讓二氧化碳通過(guò)試樣從底到頂?shù)剡M(jìn)行，隨后有的水通風(fēng)。在飽和期間處理細(xì)胞壓力被定在30kPa，并且二氧化碳和水通風(fēng)在20kPa的背面壓力使用。在試驗(yàn)中用到一個(gè)Wykeham Farrance Tritech 100應(yīng)變控制儀器，一個(gè)Wykeham Farrance交換機(jī)和AT 2000數(shù)據(jù)畫圖儀。</p><p>　　不排水三軸壓縮試驗(yàn)(CIU)是在不同試樣干燥密度，不同含水量和不同應(yīng)變比的情況下進(jìn)行

8、的。</p><p><b>　　2 試驗(yàn)結(jié)果</b></p><p>　　對(duì)于全部測(cè)試的試樣來(lái)說(shuō)，穩(wěn)態(tài)是在軸向應(yīng)變到達(dá)大約百分之二十的時(shí)候達(dá)到的，其中當(dāng)軸向的應(yīng)變繼續(xù)增加時(shí)，軸向載荷，毛孔水壓力和體積變化保持不變。除試樣有展示應(yīng)變硬化行為的200 kPa的更高鞏固壓力之外，樣品中的多數(shù)顯示應(yīng)變軟化的應(yīng)變。</p><p>　　在圖1和圖2中可

9、以看到全部試樣的穩(wěn)態(tài)行為。 這里分別表示在穩(wěn)態(tài)的偏差應(yīng)力、平均有效應(yīng)力和比體積。據(jù)研究所知，在圖上穩(wěn)態(tài)點(diǎn)趨近于一條獨(dú)特的直線。因此，對(duì)于所有的試樣在穩(wěn)態(tài)來(lái)說(shuō)，在之間有一種獨(dú)特的關(guān)系。然而，在圖上對(duì)于不同的試樣會(huì)出現(xiàn)不同的穩(wěn)態(tài)直線。所以，在圖上穩(wěn)態(tài)線是不唯一的。它取決于樣品參數(shù)和測(cè)試條件。這種趨勢(shì)的原因可能與土壤的高的好的成分有關(guān)。土壤是有高精細(xì)的一種沙，它可能不能表現(xiàn)這條穩(wěn)態(tài)線與干凈的沙相同。</p><p>　

10、　圖1 試驗(yàn)結(jié)果的關(guān)系 圖2試驗(yàn)結(jié)果的關(guān)系</p><p>　　CIU ， Rc = 90 %, Mc = 31 % ◇CIU ， Rc = 80 %, Mc = 31 % △CIU ， Rc = 80 %,</p><p>　　Mc = 28 % ×CIUF，Rc = 80 %， Mc = 31 %。</p><p>　　2.1 相對(duì)壓縮的影響&

11、lt;/p><p>　　相關(guān)的緊密程度Rc被定義為一件樣品的干燥密度和土壤的最大的干燥密度的比率。試樣的關(guān)系在相同的含水量＝31％并且不同的壓縮系數(shù)Rc可以在圖3中看到。 </p><p>　　據(jù)研究所知，可能觀察有不同的Rc的試樣有不同的穩(wěn)態(tài)行。對(duì)相同的Rc來(lái)說(shuō)，試樣的穩(wěn)態(tài)點(diǎn)傾向于集中于一條相同的穩(wěn)態(tài)線。在圖上穩(wěn)態(tài)線的位置依賴相關(guān)的緊密程度Rc。在圖中可以看到Rc越高，穩(wěn)態(tài)線越低。相關(guān)的緊密

12、程度是影響土壤的穩(wěn)態(tài)的一個(gè)重要的因素。</p><p>　　2.2 最初含水量的影響</p><p>　　試樣形成的最初含水量被定義為試樣的含水量。有相同的相關(guān)緊密程度Rc = 80％的試樣關(guān)系和不同的最初含水量成分Mc可以在圖4中看到。 </p><p>　　圖3 不同Rc試樣的關(guān)系 圖4 不同Mc試樣的關(guān)系</p><p>　　□

13、CIU , Rc = 90 %， Mc = 31 % △CIU , Rc = 80 %， Mc = 28 % ◇CIU , Rc = 80 %，</p><p>　　Mc = 31 % ◇CIU , Rc = 80 %， Mc = 31 %。</p><p>　　從數(shù)字中看出一種趨勢(shì)，盡管利用掃描儀，可能看見有相同Mc的試樣的穩(wěn)態(tài)點(diǎn)集中于一條相同的穩(wěn)態(tài)線。在圖中穩(wěn)態(tài)線的位置大多數(shù)取決于初始

14、含水量Mc。在圖中Mc越高，穩(wěn)態(tài)線越低。這表明最初含水量對(duì)土壤的穩(wěn)態(tài)有重要影響。</p><p>　　2.3 應(yīng)變比的影響</p><p>　　當(dāng)大多數(shù)試驗(yàn)在0.06毫米/分(CIU)的應(yīng)變比下執(zhí)行，幾件試樣試驗(yàn)在0.3毫米/分(CIUF)的應(yīng)變比下進(jìn)行。圖 5表現(xiàn)CIU測(cè)試的關(guān)系和CIUF試樣測(cè)試與相同Rc =80％和Mc= 31%。在圖上，看起來(lái)穩(wěn)態(tài)產(chǎn)品給CIUF測(cè)試比適合CIU測(cè)試高

15、。這暗示那個(gè)應(yīng)變比對(duì)那些土壤的穩(wěn)態(tài)有影響。在圖上，應(yīng)變比越高，穩(wěn)態(tài)線越高。</p><p>　　2.4 穩(wěn)態(tài)線的標(biāo)準(zhǔn)化</p><p>　　像上面討論的那樣，在圖上那些穩(wěn)態(tài)的松散填充在不排水三軸壓縮測(cè)試的CDV的可能被描述為獨(dú)特的直線，但是在中穩(wěn)態(tài)線并不唯一。那些穩(wěn)態(tài)線的位置依賴最初含水量，相關(guān)緊密程度和應(yīng)變比。為了更好的理解和清楚的應(yīng)用，一條單個(gè)的穩(wěn)態(tài)線在代表過(guò)程中需要。為了在圖上生成這

16、樣的一條穩(wěn)態(tài)線，一標(biāo)準(zhǔn)化方法提議在這里考慮到相關(guān)的緊密程度Rc 和最初含水量Mc的效應(yīng)。一般說(shuō)來(lái)，全部因素影響松散填充可能與標(biāo)準(zhǔn)化一起考慮到的CDV的穩(wěn)態(tài)，如果有足夠的測(cè)試數(shù)據(jù)。</p><p>　　在這項(xiàng)研究過(guò)程中，在圖上可以通過(guò)標(biāo)準(zhǔn)化結(jié)果得到一單獨(dú)的穩(wěn)態(tài)線，使結(jié)果在相同參考有關(guān)緊密程度和參考最初含水量正常時(shí)。規(guī)范化空隙比，e，可能從初始空隙比經(jīng)過(guò)固化得到，ec如下：e = ecRnMn，在這里，Rn和Mn 分

17、別標(biāo)準(zhǔn)化系數(shù)適合相關(guān)的緊密程度和最初含水量。</p><p><b>　　，，</b></p><p>　　在這里，Rcr和Rc是標(biāo)準(zhǔn)化和土壤的原先的相關(guān)的緊密程度的參考有關(guān)的緊密程度；Mcr和Mc是標(biāo)準(zhǔn)化和土壤的原先的最初含水量的參考最初含水量。 </p><p>　　對(duì)于那些CIU 測(cè)驗(yàn)結(jié)果在0.06毫米/分的應(yīng)變比，相關(guān)緊密程度Rcr 認(rèn)

18、為是80％和參考最初含水量Mcr為31％。標(biāo)準(zhǔn)化的關(guān)系可以從圖6中看出。</p><p>　　圖5 CIU和 CIUF試驗(yàn)的 關(guān)系 圖6 標(biāo)準(zhǔn)化的 關(guān)系</p><p>　　◇CIU ， Rc = 80 % , Mc = 31 % ◇CIU ， Rc = 80 % , Mc = 31 %</p><p>　　×CIUF ， Rc = 80

19、% , Mc = 31 % □CIU ， Rc = 90 % ， Mc = 31 %</p><p>　　△CIU , Rc = 80 % ， Mc = 28 %</p><p>　　在標(biāo)準(zhǔn)化之后，由于一些較小量，穩(wěn)態(tài)點(diǎn)趨近于一條直線，建議在圖上用線性獨(dú)特的穩(wěn)態(tài)線。隨著回歸分析，穩(wěn)態(tài)線在圖和圖上如下： ；。在這里標(biāo)準(zhǔn)化方法提議能用來(lái)預(yù)言穩(wěn)態(tài)松散填充與不同相關(guān)的緊密程度和最初含水量一起

20、的行為。</p><p><b>　　3 結(jié)論</b></p><p>　　基于不排水三軸壓縮試驗(yàn)在完全分解的火山土的穩(wěn)態(tài)分析中應(yīng)用，可以得到以下的結(jié)論：</p><p>　　3.1 對(duì)于不排水三軸壓縮試驗(yàn)來(lái)說(shuō)，試樣在軸應(yīng)變?yōu)榇蠹s20％時(shí)達(dá)到穩(wěn)定狀態(tài)。</p><p>　　3.2 在中穩(wěn)態(tài)線是唯一的線性的，但是在圖中并不

21、唯一。</p><p>　　3.3 在穩(wěn)態(tài)線中試樣相關(guān)壓縮程度起著很重要的影響。在圖中，越高，穩(wěn)態(tài)線越低。</p><p>　　對(duì)一個(gè)試樣多級(jí)加荷三軸剪切試驗(yàn)的探討</p><p><b>　　車 承 國(guó)</b></p><p>　　(西北電力設(shè)計(jì)院，陜西　西安　710032)</p><p>　

22、　摘要：本文簡(jiǎn)述了三軸剪切試驗(yàn)的一個(gè)試樣多級(jí)加荷剪切適用條件及在實(shí)際操作中的注意事項(xiàng)。</p><p>　　關(guān)鍵詞:三軸剪切試驗(yàn)；多級(jí)加荷；剪應(yīng)力；剪應(yīng)變；莫爾- 庫(kù)侖理論</p><p>　　三軸剪切試驗(yàn)測(cè)定土的抗剪強(qiáng)度參數(shù), 常規(guī)方法一般需要3～4個(gè)試樣， 所用試樣較多。但在實(shí)際工程中，由于某些地基或土工建筑物采取原狀土比較困難， 或因試樣的不均勻性， 難以選取3～4 個(gè)較均勻的試樣,

23、 這樣進(jìn)行常規(guī)三軸試驗(yàn)就受到了限制?！锻凉ぴ囼?yàn)方法標(biāo)準(zhǔn)》GB/T50123 - 1999 允許采用一個(gè)試樣多級(jí)加荷試驗(yàn)測(cè)定抗剪強(qiáng)度參數(shù)， 由于避免了試樣之間的差異，所測(cè)得的成果比較規(guī)律, 強(qiáng)度包線易于繪制, 比多個(gè)試樣三軸試驗(yàn)有一定的優(yōu)點(diǎn)。但這種做法有一定的適用條件, 本文就此進(jìn)行了試驗(yàn)分析和理論探討。</p><p>　　三軸試驗(yàn)中一個(gè)試樣多級(jí)剪切的適用性分析</p><p>　　常規(guī)三

24、軸剪切試驗(yàn)的原理基于材料力學(xué)中的雙軸應(yīng)力狀態(tài)理論</p><p>　　試驗(yàn)中保持σ3 不變， 不斷增加σ1，直至試樣在α= 45°+φ2 面上剪切破壞為止。剪切破壞的標(biāo)準(zhǔn)是τa =τf 對(duì)于砂石料、硬土、超固結(jié)土， 試樣在剪切破壞時(shí)的現(xiàn)象是十分清楚的， 它們的剪應(yīng)力與應(yīng)變關(guān)系如圖1 的曲線①所示， 即隨著剪應(yīng)變的增加， 剪應(yīng)力也增加， 當(dāng)剪應(yīng)力達(dá)到土的抗剪強(qiáng)度τ后， 隨著剪應(yīng)變?cè)黾樱?土的剪應(yīng)力呈下降趨

25、勢(shì)。因此， 在試驗(yàn)和資料分析中容易判定其抗剪強(qiáng)度τf 。但對(duì)于一些有剪切硬化性質(zhì)的粘土、軟土，它的應(yīng)力、應(yīng)變關(guān)系如曲線②所示。在曲線②上</p><p>　　圖1 剪應(yīng)力與應(yīng)變關(guān)系圖</p><p>　　我們無(wú)法得到峰值點(diǎn)， 即無(wú)法直觀判定土的抗剪強(qiáng)度τf 值。為此， 工程上采用了應(yīng)變破壞標(biāo)準(zhǔn)，即當(dāng)土的應(yīng)變達(dá)到某個(gè)值后， 雖然未出現(xiàn)剪應(yīng)力峰值， 但也認(rèn)為土樣已破壞， 相應(yīng)應(yīng)變下的剪應(yīng)力就可

26、確定為土的抗剪強(qiáng)度值。而這個(gè)破壞應(yīng)變， 工程上一般可依工程的重要性不同而選為10 %、15 %和20 %。以上論述是討論一個(gè)樣多級(jí)剪的基礎(chǔ)。其次， 用莫爾- 庫(kù)侖理論整理三軸試驗(yàn)資料時(shí)， 同一組試樣在剪切破壞時(shí)的破裂面a= 45°+φ2 相等也是討論一個(gè)樣多級(jí)剪的基礎(chǔ)。下面是分析的結(jié)論:</p><p>　　1) 一個(gè)樣多級(jí)三軸剪的適用土樣為砂石料土、硬土和超固結(jié)土(一般粘土在低圍壓固結(jié)條件下剪切時(shí)也有

27、剪應(yīng)力峰值存在，但實(shí)質(zhì)上屬于超固結(jié)定義的范疇)。因?yàn)閷?duì)于這些土，剪切破壞時(shí)相應(yīng)的剪應(yīng)變小，因而分級(jí)剪切后的累計(jì)剪應(yīng)變也不至過(guò)大(一般不超過(guò)20 %)。同時(shí)，各級(jí)的剪切破壞面為同一破壞面，符合莫爾- 庫(kù)侖理論。</p><p>　　2) 對(duì)于軟土、有剪切硬化性質(zhì)的粘土， 因?yàn)樵诩羟袝r(shí)不出現(xiàn)剪切峰值， 無(wú)法直接判斷在該級(jí)圍壓下的抗剪強(qiáng)度， 若采用應(yīng)變破壞標(biāo)準(zhǔn)確定抗剪強(qiáng)度τf ， 勢(shì)必分級(jí)累積的破壞應(yīng)變過(guò)大而不符合工程

28、要求和規(guī)范值(如前述的10 %、15 %、20 %)，反之， 若滿足累積破壞應(yīng)變標(biāo)準(zhǔn)， 勢(shì)必要降低抗剪強(qiáng)度值， 這也就是為什么一樣多剪求的抗剪強(qiáng)度指標(biāo)偏小的主要原因。其次， 對(duì)于軟土、有剪切硬化性質(zhì)的粘土， 三軸剪切時(shí)破裂面的位置隨所選的應(yīng)變值不同而不同。這時(shí)， 一樣多剪時(shí)各級(jí)圍壓下確定的抗剪強(qiáng)度具有不同的破裂面位置。經(jīng)過(guò)資料整理校正后雖具有相同的破裂面， 但對(duì)莫爾- 庫(kù)侖理論來(lái)說(shuō)是較勉強(qiáng)的。</p><p>　

29、　2 三軸試驗(yàn)中一個(gè)試樣多級(jí)剪切的試驗(yàn)驗(yàn)證</p><p>　　本試驗(yàn)依據(jù)GB/ T50123 - 1999《土工試驗(yàn)方法標(biāo)準(zhǔn)》， 使用南京土壤儀器廠TSZ 30 - 210型臺(tái)式三軸儀及其TWJ - 1型土工試驗(yàn)微機(jī)數(shù)據(jù)采集處理系統(tǒng)。</p><p>　　典型的試驗(yàn)結(jié)果如圖2、圖3 所示: 飽和試樣強(qiáng)度包線如圖4 所示 </p><p><b>　　圖2

30、 人工制備樣</b></p><p><b>　　圖3 原狀飽和樣</b></p><p>　　圖4 飽和粉土強(qiáng)度包線</p><p>　　從圖2、圖3所示的試驗(yàn)結(jié)果中， 說(shuō)明了上述分析結(jié)論。從表1中選取部分試驗(yàn)強(qiáng)度包線如圖4 列舉所示， 對(duì)于飽和粉土的一個(gè)試樣多級(jí)加荷試驗(yàn)亦應(yīng)持謹(jǐn)慎態(tài)度。對(duì)于一個(gè)試樣多級(jí)加荷試驗(yàn)在何條件下(如各級(jí)應(yīng)

31、變的控制范圍等)能與實(shí)際的常規(guī)三軸試驗(yàn)抗剪強(qiáng)度更能接近， 還有待于進(jìn)一步分析、對(duì)比和探討， 由于常規(guī)試驗(yàn)對(duì)試樣的均勻性要求較高， 因而也是有一定的難度， 還需在條件許可的情況下， 逐步進(jìn)行。</p><p><b>　　3 結(jié)論及建議</b></p><p>　　1) 一樣多剪的三軸試驗(yàn)適用于硬土、超固結(jié)土， 對(duì)于高含水量的粘性土(粉土) 一般不能采用這種試驗(yàn)方法。&

32、lt;/p><p>　　2) 試驗(yàn)中應(yīng)注意如下事項(xiàng)：</p><p>　?、賹?duì)CU 試驗(yàn)， 為使試驗(yàn)恢復(fù)到等向固結(jié)狀態(tài)， 必須退去上級(jí)剪切時(shí)的軸向壓力， 待孔壓達(dá)穩(wěn)定后再施加下一級(jí)圍壓， 而后級(jí)固結(jié)圍壓應(yīng)大于前級(jí)圍壓下破壞時(shí)的大主應(yīng)力。對(duì)于UU 試驗(yàn)則不需退去前級(jí)軸向壓力。</p><p>　?、趯?duì)于CU試驗(yàn)，第一級(jí)圍壓最好采用50kPa。</p><

33、;p>　　③對(duì)于UU 試驗(yàn)，通常無(wú)特殊要求時(shí)， 第一級(jí)圍壓可取50或100kPa，以后各級(jí)可按第一級(jí)圍壓的1～3倍遞增。下級(jí)圍壓施加之后應(yīng)穩(wěn)定10～20分鐘再進(jìn)行剪切， 以消除前級(jí)剪切的影響。施加第二級(jí)或以后各級(jí)圍壓的剪切試驗(yàn)， 應(yīng)注意控制在第一級(jí)圍壓下的剪切破壞的到達(dá)和剪應(yīng)變的大小。對(duì)于脆性破壞的結(jié)構(gòu)性強(qiáng)的試樣，破壞應(yīng)變一般小于5% ， 甚至小于3 %。對(duì)于塑性破壞的試樣， 破壞應(yīng)變可控制在5%～7%。</p>&

34、lt;p><b>　　附錄B 外文文獻(xiàn)</b></p><p>　　Triaxial Compression Test on Steady State Behavior of Saturated CDV Soils</p><p>　　ZHAI Yang1, LE Zhuofen2, Luo Jintian3</p><p>　　(1.C

35、onstruction Office, Yantai University, Yantai 264005, China; 2.Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong,China; 3. Department of Civil and Environmental Engineering, Carleton

36、University, Ottawa, Ontario, K1S 5B6, Canada)</p><p>　　Abstract: Based on a comprehensive triaxial untrained compression test program on remolded specimens, the steady state of CDV loose fills was analyzed.

37、The effect of relative compaction, initial moisture content of specimens and strain rate was investigated. A normalization method is proposed to produce a unique steady state line inconsiderate on of the effect of relati

38、ve compaction and initial moisture content.</p><p>　　Key words: completely decomposed volcanic; loose fill; steady state</p><p>　　CLC Number : TU 43 Document Number : A</p><p>　　Th

39、e completely decomposed volcanic (CDV) residual soil is one of the main fill materials used for roads and fill slopes in Hong Kong. Before 1970’s, many fill slopes were commonly constructed without compaction. In 1970’s,

40、 two catastrophic event s of flow slides took place in fill slopes built in 1960’s. The cause of such slides has been attributed to static liquefaction [1, 2]. Since there are still many loose fill slopes of this kind ex

41、isting in the area, for the purpose of upgrading and remed</p><p>　　The steady state is an important concept in the analysis of static liquefaction and collapse behavior of soils. It can be represented by a

42、line in the p′～ q～υ space , or on the q～ p′ and the υ～log p′ plots. Where p′= ( + 2 ) / 3, q =- and υ= 1 + e. The uniqueness of steady state line is a controversial issue. Some studies [3, 4] show that the steady state

43、line is unique. On the other hand, some studies show that the steady state line is not unique and depends on factors such as dry density, str</p><p>　　1 Testing Program</p><p>　　The soil used in

44、 this test program was obtained from Tai Mong Tsai Road, New Territories, Hong Kong. It is a kind of completely decomposed volcanic residual soil. The optimum moisture content is 31 %; the maximum dry density is 1. 36 Mg

45、/ m3, the particle density is 2. 68 Mg/ m3 and the clay content is 41 %.</p><p>　　The specimens were formed with the moist tamping method, and the dimensions were 76 mm in diameter and 152 mm in height. Spec

46、imens were compacted in five layers at a certain moisture content. After the initial density was selected and the total weight computed, each layer was carefully compacted to the same thickness with the same amount of so

47、il. Specimen saturation was carried out by passing carbon dioxide through the specimen from the bottom to the top, followed by de-aired water. During the s</p><p>　　2 Test Results</p><p>　　For a

48、ll the specimens tested, the steady state was reached at the axial strain of about 20 %, where the axial load, pore water pressure and volume change remained constant, as the axial strain continued to increase. The major

49、ity of the specimens displayed strain softening behavior, except the specimens with a higher consolidation pressure of 200 kPa which displayed strain hardening behavior. The steady state of all specimens on the ～ and ～l

50、og plot are shown in Fig.1 and Fig.2. Here, and are </p><p>　　2. 1 Effect of Relative Compaction</p><p>　　The relative compaction is defined as the ratio of the dry density of a specimen to

51、the maximum dry density of the soil. The ～log relationship of specimens with the same moisture content = 31 % and different relative compaction is shown in Fig. 3.</p><p>　　It can be observed that specim

52、ens with different have different steady state lines. For the same, the steady state points of specimens tend to converge to a same steady state line. The location of the steady state line on the～log plot is dependent

53、on the relative compaction . The higher the is, the lower is the steady state line on the plot. The relative compaction is an important factor affecting the steady state of the soil.</p><p>　　2. 2 Effect of

54、 Initial Moisture Content</p><p>　　The initial moisture content is defined as the moisture content with which the specimen is formed. The ～log relationship of specimens with the same relative compaction = 80

55、 % and different initial moisture content is shown in Fig. 4.</p><p>　　From this figure, a trend, although with some scatter, can be seen that the steady state points of specimens with the same converge to

56、 a same steady state line. The location of steady state line on the ～log plot is, mostly, dependent on the initial moisture content .The higher the is, the lower is the steady state line on the plot. This means that the

57、 initial moisture content has an important effect on the steady state of the soil.</p><p>　　2. 3 Effect of Strain Rate</p><p>　　While the majority of the tests were conducted at a strain rate of

58、 0. 06 mm/ min (CIU), several specimens were tested at a faster strain rate of 0. 3 mm/min (CIUF). Fig. 5 shows the ～log relationship of CIU tests and CIUF tests of specimens with the same = 80 % and = 31 %. It appear

59、s that the steady state line for CIUF tests is higher than that for CIU tests on the ～log plot . This implies that the strain rate has an effect on the steady state line of the soil. The higher the strain rate is </p

60、><p>　　2. 4 Normalization of Steady State Line</p><p>　　As discussed above , the steady state of CDV loose fills tested in triaxial untrained compression can be represented by a unique straight lin

61、e on the ～ plot , but it is not unique on the ～log plot . The location of steady state line is dependent on relative compaction, initial moisture content and strain rate. For the purpose of better understanding and cle

62、ar application, a single steady state line is needed in representation. To produce such a line on the ～log plot , a normalization method i</p><p>　　In which, and are the reference relative compaction for

63、normalization and the original relative compaction of the soil; and are the reference initial moisture content for normalization and the original initial moisture content of the soil.</p><p>　　For the CIU t

64、est results at a strain rate of 0. 06 mm/min, the reference relative compaction is taken as 80 % and the reference initial moisture content as 31 %. The normalized ～log relationship is shown in Fig. 6.</p><

65、p>　　After normalization, with some minor scatter , the steady state point s tend to converge to a straight line, suggesting a linear unique steady state line on the ～log plot. With regression analysis, the steady sta

66、te line equation on the ～ and ～log plot are given as: = 1. 42; = 2. 575 - 0. 122ln. </p><p>　　The normalization method proposed here could be used to predict the steady state behavior of loose fills with

67、 different relative compactions and initial moisture contents.</p><p>　　3 Conclusions</p><p>　　Based on the triaxial untrained compression test s on steady state of a completely decomposed volca

68、nic, the following conclusions can be drawn:</p><p>　　3. 1 For triaxial untrained compression tests, specimens reached the steady state at the axial strain of about 20 %.</p><p>　　3. 2 The stead

69、y state line of specimens is a unique linear line on the ～ plot , but it is not unique on the ～log plot .</p><p>　　3. 3 The relative compaction of specimens () has an important effect on the steady state l

70、ine. The higher the is , the lower is the steady state line on the ～log plot .</p><p>　　3. 4 The initial moisture content of specimens () affect s the location of steady state line. The higher the is , th

71、e lower is the steady state line on the ～log plot .</p><p>　　3. 5 Compared with the CIU tests, the CIUF tests give a higher steady state line on the ～log plot .</p><p>　　3. 6 A normalization m

72、ethod taking into account of the relative compaction and the initial moisture content has been proposed to produce a single steady state line on the ～log plot .</p><p>　　Acknowledgment</p><p>　

73、　The content of this paper is based in part on the Ph. D work of the first author under the supervision of the last two authors. The tests were conducted in the soil laboratory of Civil Engineering Department, the Univer

74、sity of Hong Kong. The assistance provided by the University is sincerely acknowledged.</p><p>　　References:</p><p>　　[1] Government of Hong Kong. Report on the Slope Failures at Sau Mau Ping, A

75、ugust, 1976, [R]. Hong Kong: Government of Hong Kong, 1977.</p><p>　　[2] Lumb P. Slope failure in Hong Kong [J]. Quartly Journal of Engineering Geology , 1975 , 8 : 31～65.</p><p>　　[3] Casagrand

76、e A. Liquefaction and cyclic deformation of sands: A critical review [J]. Harvard Soil Mechanics Series, 1975, 88, (Special Volume).</p><p>　　[4] Poulos S J. Castro G, France J W. Liquefaction evaluation pr

77、ocedure [J]. Journal of Geotechnical Engineering , ASCE , 1985 , 116 (6) : 722～792.</p><p>　　[5] Yamamuro J A, Lade P V. Steady- State concepts and static liquefaction of silly sands [J]. Journal of Geotechn

78、ical and Environmental Engineering , ASCE , 1998 , 124 (9) : 868～877.</p><p>　　[6] Vaid Y , Chung E K F, Kuerbis R H. Stress path and steady state [J]. Canadian Geotechnical Journal, 1990 , 27 :1～7.</p>

79、;<p>　　[7] Riemer M F, Seed R B. Factors affecting the apparent position of steady state line [J]. Journal of Geotechnical and Geoenvironmental Engineering , ASCE , 1997 ,123 (3) : 281～288.</p><p>　　[

80、8] Konrad J M. Minimum untrained strength of two sands [J]. Journal of Geotechnical Engineering, ASCE , 1990 , 116 (6) :932～947.</p><p>　　[9] Hird C C, Hassona F A K. Some factors affecting the liquefaction

81、and flow of saturated sands in laboratory Tests [J]. Engineering Geology , 1990 , 28 :149～170. </p><p>　　Discussion of Triaxial Shear Test for Multilevel Adding Load of a Kind of Samples</p><p>

82、　　CHE Chengguo</p><p>　　(Northwest Electric Power Design Institute, Xian 710032, China)</p><p>　　Abstract: The article recounts noticing details about the applying condition and operating proce

83、ssion in practice. The above condition and operating procession is conclusion to the multilevel adding load of a kind of samples among the triaxial sheerest.</p><p>　　Key words: triaxial shear test; multiple

84、2stage loading; shear stress; shear strain; Mohr2Coulomb theory</p><p>　　Three stalks shear to slice that experiment measures the soil to shear the strength parameter, the normal regulations method needs gen

85、erally 3to4 try the kind, uses to try the kind more. But in actual engineering, adopt the original shape soil the comparison the difficulty because of some foundations or soil work buildings, or because try the asymmetry

86、 of the kind, and is hard to select by examinations 3 to4 than try the kind evenly, proceed the normal regulations like this three stalks experime</p><p>　　1 Three stalks experiment inside an applicability f

87、or trying kind many class shearing slicing analysis</p><p>　　Normal regulations three stalks shear to slice the on trial principle according to material a stalk should dint appearance theories</p><

88、;p>　　Experimenting the inside keeps σ 3 constant, increase the σ continuously 1, keep to try the kind to shear to slice the breakage in α= 45°+φ2 Shearing to slice destructive standard is anti- that τ a= the τ f

89、increases freestone anticipate, hard soil, super knot soil, try kind at shear phenomenon that slice breakage hour is very clear, their shear should dint with adapts to changes relation, such as figure,1 of curve ① show,

90、namely along with shear emergency increment, shear should dint very much,</p><p>　　We can't get the value orders, can't keep namely the anti- that view judge soil shear the strength τ f the value. Fo

91、r this, on the engineering adoption adapt to changes breakage standard, then the soil adapts to changes to attain a certain value behind, although did not appear to shear should dint value, also think that the soil kind

92、has broken, the cowgirl adapts to changes bottom of shear should dint can make sure to shear the strength the value for the of the soil. But this breakage adapts to</p><p>　　1) A kind many classes three the

93、suitable for use soil kind that stalks shears anticipate the soil, hard soil for the freestone with the super knot soil.( glue the soil generally at low round to press the knot term descend to shear to slice also shear s

94、hould the dint value exists, but belong to the category that super knot definition substantially)Because shear these soils, shear slice hour of breakage very much to adapt to changes small, as a result the ratings shears

95、 to adapt to changes after </p><p>　　2) Judge soft soil, have shear slice hardening kind glue soil, because at shear slice do not appear shear slice value, can't very much to round in that class that pre

96、ss down shear the strength, if the adoption adapts to changes the certain anti- in standard in breakage shears the strength τ f, certainly will the breakage of the ratings accumulation adapts to changes big but not agree

97、 with to match the engineering request much more similar to norm value (such as above 10%,15%,20%), whereas, if sa</p><p>　　2 Three stalks experiment inside an on trial verification for trying kind many clas

98、s shearing slicing</p><p>　　Experiment to gather to see the table with soil and projects 1</p><p>　　This experiment according to the GB/ T50123- 1999 《 soil works experiment the method standard

99、》 , usage Nan king soil instrument factory TSZ 30- 210 Type set type three stalk s and its TWJ- 1 The type soil work experiments the tiny machine data collects to handle system.</p><p>　　Typical and on trial

100、 result, such as figure,2, figure 3 show: The saturation tries the kind strength a line, such as figure,4 show:</p><p>　　From the figure 2, figure 3 the on trial result inside that show, explained the above

101、analysis conclusion. From the table 1 win election to take the part of experimenting the strength a line such as Figure 4 enumerate to show, for saturated powder soil of a tries kind many classes adds the experiment to a