517157517157
本發明係一種用於測定土壤塑性限度的方法。 (先前技術） 測疋土。壤塑性限度的傳統方法為搓土條法㈧… 8 8)彳一為方法執行時嚴重牽涉到操作人員之主觀判The invention is a method for determining the plastic limit of soil. (Prior art) Test soil. The traditional method of soil plasticity limit is the rubbing method ... 8 8) One is the subjective judgment of the operator when the method is executed.
英製標準落錐（80公克、錐尖角30。）係用於測定細 粒土壤的液性限度（英國試驗規範ι 377:1 99〇)，且試 ，時使用盛土杯（5 5釐米内徑、4 0釐米高），當落錐貫入量 $於2 0厘米日守，土樣之含水量即為液性限度。英國試驗須 範私出’使用盛土杯製作試樣必須注意不使試樣含有氣 泡，可見使用盛土杯有其不便利之處，且此不便利性产 樣含水量之減少而增加，因為土樣含水量愈少則愈^ 易置入盛土杯中。 向$ (發明概述） 英國試驗規範BS 1 377: 1 990 )，但改以特製之盛土 本發明係一種使用落錐（如圖1所示）測定土壌塑性 度的方法，仍使用·英製標準落錐（80公克、錐尖角3〇’。限 . -—環取处 盛土杯’使此簡易客觀地製作試樣來進行落錐貫入 測定土壤塑性限度。盛土環可以用不銹鋼或紹製成=、驗以 本方法是利用盛土環（高2公分，内徑2公分，—山 薄成刀刃狀；如圖2 A所示）製作試樣，由於其内容積端削 因此僅需少量土樣即可進行試驗。將落錐自土壤' + ’ A樣表面The inch standard drop cone (80 g, cone tip angle 30) is used to determine the liquid limit of fine-grained soil (British Test Code 377: 1 99〇), and when the test, use a soil cup (within 5 5 cm) Diameter, 40 cm height), when the falling cone penetration is $ 20 cm, the water content of the soil sample is the liquid limit. The British test must be performed privately. 'Using soil cups to make samples must be careful not to make the samples contain air bubbles. It can be seen that using soil cups has its inconveniences, and the inconvenience of the production sample is reduced and the water content is increased. The less the water content, the easier it is to place it in a soil cup. To $ (Overview of the Invention) British Test Specification BS 1 377: 1 990), but changed to a special soil. The present invention is a method for measuring the plasticity of soil concrete using a falling cone (as shown in Figure 1). The British standard is still used. Drop cone (80 g, cone tip angle 30 '. Limit. --- ring take place soil cup' make this simple and objective to make a sample to carry out drop cone penetration to determine the soil plastic limit. The soil ring can be made of stainless steel or Shao = The test method is to use the soil ring (2 cm high, 2 cm inside diameter,-mountain thin into a blade shape; as shown in Figure 2 A) to make a sample, because its internal volume is cut, only a small amount of soil sample is required Test is ready. Drop cone from soil '+' A-like surface
517157 ~五、發明說明（2) ' ' · - 落下> 而貫入試樣，進行4次試驗使貫入深度約略均勻分佈 在4胃釐米至1〇釐米之間，而獲得4組貫入深度與土壤試樣含 水量之數據，據之外插而推估塑性限度。 (發明的詳細說明） 本發明係一種用於測定土壤塑性限度的方法，包含以 一盛土環（如圖2 A所示）製作試樣，將重模的土樣用藥刀或 雙手形成一近似圓柱略大於盛土環之塊體，再將盛土環置 於其上（刀刃端向下如圖2B所示），然後以雙手將盛土環向 下推壓使完全貫入土樣之中，將土樣突出於盛土環頂部之 部份以線鋸或刮刀除去而得一平整之試樣表面（圖2 c所 示）’再將落錐置於試樣表面中心點之上方（圖2 D所示）， 降下落錐使與試樣表面些微接觸，最後使落錐自由落下而 貫入試樣中。 盛土環的内容積僅約6 · 3立方公分，因此進行一次僅 約需2 0公克的濕土，且一端削薄成刀刃狀可使盛土環輕易 貝入土樣之中’此一特點使含水量較接近塑性限度之試樣 很容易被製成。本方法訂限定落錐貫入深度在4 —丨〇釐米範 圍内之試驗結果方為合格，而在此範圍内土樣因含水量漸 接近塑性限度而愈來愈硬，已不適合用盛土杯製作試樣。517157 ~ V. Description of the invention (2) ''--Drop > While penetrating the sample, perform 4 tests to make the penetrating depth approximately evenly distributed between 4 stomach cm to 10 cm, and obtain 4 groups of penetrating depth and soil The data of the moisture content of the sample is extrapolated to estimate the plasticity limit. (Detailed description of the invention) The present invention is a method for determining soil plasticity limit, which includes preparing a sample with a soil ring (as shown in FIG. 2A), and forming an approximated soil sample with a medicine knife or both hands to form an approximation. The cylinder is slightly larger than the block containing the soil ring, and then the soil ring is placed on it (the blade end is downward as shown in Figure 2B), and then the soil ring is pushed down with both hands to completely penetrate the soil sample, and the soil The part of the sample protruding from the top of the soil ring was removed with a wire saw or a scraper to obtain a flat sample surface (shown in Figure 2c). Then the drop cone was placed above the center point of the sample surface (shown in Figure 2D). ), Drop the drop cone to make slight contact with the surface of the sample, and finally let the drop cone fall freely and penetrate into the sample. The inner volume of the soil ring is only about 6.3 cubic centimeters, so it only takes about 20 grams of wet soil to perform one time, and one end is thinned into a blade shape to allow the soil ring to easily enter the soil sample. Samples with a water content closer to the plastic limit are easily made. The test results are qualified only if the penetration depth of the falling cone is within the range of 4-0 cm. In this range, the soil sample becomes more and more hard because the water content is gradually approaching the plastic limit. kind.
Hansbo (1957 ’SGI Proceeding， No· 14)指出不排 水剪力強度與落錐貫入量之平方成反比，且Skempt⑽&Hansbo (1957 ’SGI Proceeding, No. 14) pointed out that the non-draining shear strength is inversely proportional to the square of the penetration of the falling cone, and Skempt⑽ &
Northey (1953, Geotechnique，Vol· 3，No. 1)指出土壤 於塑性限度之不排水剪力強度為於液性限度之不排水剪力^Northey (1953, Geotechnique, Vol. 3, No. 1) pointed out that the undrained shear strength of the soil at the plastic limit is the undrained shear force at the liquid limit ^
517157 五、發明說明（3) 強度之1 00倍。依據上述之理論背景，可知落錐（80公克、 錐尖角3 0 ° )貫入深度為2 0釐米的1 / 1 0，即2釐米時土壤試 樣之含水量為其塑性限度。為推估土壤塑性限度，本發明 係包含於貫入深度4-10釐米的範圍内進行4次試驗，而獲 得4組落錐貫入深度與土壤試樣含水量之數據，4個貫入深 度應約略均勻分佈在4-1 0釐米之間。將此4組數據畫在貫 入量與落錐貫入深度的雙對數圖中，對之進行線性迴歸分 析而得一線性關係（如圖3所示範例），據之外插而推得對 應於2釐米貫入深度之含水量，此含水量即為塑性限度。 經利用數種土樣進行試驗而獲得相關數據，其迴歸分析所 得線性關係R2值皆大於0. 9 5。517157 V. Description of the invention (3) 100 times stronger. According to the above theoretical background, it can be seen that the falling cone (80 g, cone angle 30 °) penetrates to a depth of 1/10 of 20 cm, that is, the water content of the soil sample at 2 cm is its plastic limit. In order to estimate the limit of soil plasticity, the present invention includes 4 tests in the range of penetration depth of 4-10 cm, and obtains the data of the penetration depth of the 4 cones and the water content of the soil sample. The penetration depth of the 4 penetrations should be approximately uniform. Distributed between 4 and 10 cm. Draw the 4 sets of data in a double logarithmic plot of penetration and penetration depth of the falling cone, and perform a linear regression analysis on it to obtain a linear relationship (example shown in Figure 3). Extrapolate it to correspond to 2 The water content of centimeter penetration depth, this water content is the plastic limit. Relevant data were obtained after experiments using several soil samples, and the linear relationship R2 values obtained by regression analysis were all greater than 0.95.
517157 圖式簡單說明 第1圖為試驗所用之圓錐（8 0公克、錐尖角3 0 ° )。 第2A圖為試驗所用之盛土環（高2公分，内徑2公分，一端 削薄成刀刃狀）。 第2B圖為盛土環置於近似圓柱形重模土樣之上方，其刀刃 端向下。 第2C圖為盛土環貫入近似圓柱形重模土樣之中，直至底 部，後將頂部多餘土樣去除，而得一平整之試樣表面。 第2D圖為將圓錐置於試樣表面中心點上方。之後降下圓錐 使與試樣表面些微接觸。 第3圖為貫入深度與含水量的雙對數關係直線，其對應於2 釐米貫入深度的含水量即為塑性限度。517157 Brief description of the drawing Figure 1 shows the cone used in the test (80 g, cone angle 30 °). Figure 2A shows the soil ring used in the test (2 cm in height, 2 cm in inner diameter, and one end thinned into a blade shape). Figure 2B shows the soil ring placed above the approximately cylindrical heavy mold soil sample with the blade end facing downward. Figure 2C shows that the soil circle penetrates into the approximately cylindrical heavy mold soil sample to the bottom, and then removes the excess soil sample from the top to obtain a flat sample surface. Figure 2D shows the cone placed above the center point of the sample surface. Then lower the cone to make slight contact with the surface of the specimen. Figure 3 is a double logarithmic straight line of penetration depth and water content. The water content corresponding to penetration depth of 2 cm is the plastic limit.