本文關(guān)鍵詞：火山噴出物發(fā)育土壤的比重及顆粒組成的特征研究　出處：《沈陽農(nóng)業(yè)大學》2017年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 火山灰土 土壤比重 土壤顆粒組成 靜水沉降法 篩析法

【摘要】：在對火山噴出物發(fā)育土壤進行系統(tǒng)分類時,為了判斷是否為火山灰土,需要對土壤樣品進行火山灰特性的判定�；鹕交姨匦允且幌盗行再|(zhì)的集合。在某種條件下,判定土壤是否具有火山灰特性,需要測定其2～0.02 mm粒級的含量。然而,現(xiàn)行火山灰特性的鑒定標準中沒有明確規(guī)定土壤顆粒組成的測定方法。本研究以東北地區(qū)新生代噴發(fā)的玄武巖質(zhì)和粗面巖質(zhì)火山噴出物發(fā)育土壤為研究對象,測定兩種巖性土壤小于0.1 mm和小于1 mm兩個粒徑范圍土粒的比重,并進行土壤顆粒組成測定方法的研究與比較,以期為修訂和完善火山灰特性的鑒定標準提供科學依據(jù)。研究結(jié)果表明:(1)玄武巖質(zhì)火山噴出物發(fā)育的土壤,較高發(fā)育程度的、粒徑小于0.1 mm和粒徑小于1 mm 土粒的比重分別為2.78 g cm-3和2.62 g cm-3;低發(fā)育程度的、粒徑小于0.1 mm和粒徑小于1 mm 土粒的比重分別為2.62 gcm-3和2.55 gcm-3。弱發(fā)育程度的粗面巖質(zhì)火山噴出物發(fā)育的土壤,粒徑小于0.1 mm和粒徑小于1 mm 土粒的比重分別為2.56 g cm-3和2.50 g cm-3。同種巖性發(fā)育的土壤,粒徑小于0.1 mm 土粒的比重較粒徑小于1 mm 土粒的比重大。相同粒徑范圍的土粒,玄武巖質(zhì)火山噴出物發(fā)育土壤的比重較粗面巖質(zhì)火山噴出物發(fā)育土壤的比重大。土壤比重值隨著土壤發(fā)育程度的加強而增大。(2)靜水沉降法測定火山噴出物發(fā)育土壤的顆粒組成時,需要實測粒徑小于0.1 mm土粒的比重,進而計算各粒級土粒的沉降時間。實驗數(shù)據(jù)統(tǒng)計分析表明:依據(jù)斯托克斯定律,在其他條件不變的情況下,比重每增加0.01個單位,較粗顆粒(0.05 mm、0.02 mm)沉降時間縮短1～2 s;黏粒(0.002 mm)縮短約5 min。水溫每增加1 ℃沉降時間縮短9～12 min左右。(3)基于粒徑小于1 mm土粒比重測定的砂粒、粉粒和黏粒的含量,與基于2.65 gcm-3的比重值測定的各顆粒含量的平均差值分別為17.99gkg-1 15.99gkg-1和14.1gkg-1;基于粒徑小于0.1 mm 土粒比重測定的砂粒、粉粒和黏粒的含量,與基于2.65 g cm-3的比重值測定的各顆粒含量的平均差值分別為15.3 g kg-1 13.8 g kg-1和13.2 g kg-1 土壤比重值對土壤各粒級含量的影響程度為:砂粒粉粒黏粒,進而影響土壤質(zhì)地定名,當土壤比重值改變0.01個單位時,就可能影響質(zhì)地的命名。(4)基于粒徑小于0.1 mm 土粒比重的靜水沉降法測定的粒級含量與篩析法測定的同粒級含量相比,大多數(shù)土壤樣品篩析法比靜水沉降法測定的含量偏粗,篩析法和靜水沉降法在大粒徑(0.5～0.05 mm)的絕對誤差含量相對較大,小粒徑級(0.05～0.02 mm)的絕對誤差含量相對較小。由于不同方法測定的粒級含量存在差距,所以,火山灰特性中需要明確規(guī)定土壤顆粒含量的測定方法。
[Abstract]:In order to determine whether the volcanic ash soil is a volcanic ash soil, a systematic classification of volcanic exhalation soil is carried out in order to determine whether it is a volcanic ash soil or not. It is necessary to judge the volcanic ash characteristics of soil samples. The volcanic ash characteristics are a set of properties. Under certain conditions, it is determined whether the soil has volcanic ash characteristics. It is necessary to determine the content of its 2 ~ (2) O ~ (2 +) ~ (2) mm particle size. There is no clear method for determining the composition of soil particles in the current criteria for determining the characteristics of volcanic ash. In this study, basaltic and coarse-surfaced volcanic exhalations from Cenozoic eruptions in Northeast China were studied. The specific gravity of soil particles in the range of less than 0.1 mm and less than 1 mm in two lithologic soils was measured, and the determination methods of soil particle composition were studied and compared. In order to provide scientific basis for revising and perfecting the identification standard of volcanic ash characteristics, the research results show that the soil developed by basaltic volcanic exhalation is of higher development degree. The specific gravity of soil particles with particle size less than 0. 1 mm and less than 1 mm were 2.78g cm-3 and 2.62g cm-3, respectively. Of low development. The specific gravity of soil particles smaller than 0. 1 mm and less than 1 mm were 2.62 gcm-3 and 2.55, respectively. Gcm-3. Soils with a weak degree of development of coarse-faced volcanic eruptions. The specific gravity of soil particle size less than 0. 1 mm and less than 1 mm is 2.56g cm-3 and 2.50g cm ~ (-3), respectively. The specific gravity of soil particles with diameter less than 0.1 mm is larger than that of soil particles with diameter less than 1 mm. The proportion of soil developed by basalt volcanic exhalation is larger than that by coarse-faced volcanic exhalation. The soil specific gravity value increases with the enhancement of soil development degree. The particle composition of the soil developed by volcanic ejection was determined by static water sedimentation method. It is necessary to measure the specific gravity of soil particle size less than 0.1 mm, and then calculate the settlement time of each particle. The statistical analysis of the experimental data shows that: according to Stokes' law, under other conditions unchanged. When the specific gravity increases by 0.01 units, the settling time of the coarse particles is shortened by 1 ~ 2 s than that of the coarse particles by 0.05 mm ~ 0.02 mm. Clay (0.002 mm) is shortened by about 5 mins, and the sedimentation time of water is shortened by 9 ~ 12 min for each increase of water temperature. The sand is measured based on the specific gravity of soil particle size less than 1 mm. The content of powder and clay. The average difference of particle content was 17.99gkg-1 15.99gkg-1 and 14.1gkg-1, respectively, compared with the specific gravity value based on 2.65 gcm-3. The content of sand, silt and clay based on the specific gravity of soil particle less than 0.1 mm. The average difference between the particle content and the specific gravity value based on 2.65 g cm-3 was 15.3 g kg-1 13.8g kg-1 and 13.2 g kg-1, respectively. The influence of soil specific gravity on the content of soil particles is as follows: sand silt clay. Then the soil texture was named, when soil specific gravity changed 0.01 units. For the nomenclature that may affect texture, the particle size content determined by the hydrostatic sedimentation method based on the specific gravity of soil particles less than 0.1 mm is compared with that of the same grain size content determined by the sieve analysis method. Most soil sample sieve analysis method than static water sedimentation method to determine the content of coarse, sieve out method and static water sedimentation method in the large particle size of 0.5 ~ 0.05 mm) the absolute error content is relatively large. The absolute error content of 0.05 ~ 0.02 mm) is relatively small. Because of the difference between different methods, the content of particle size is different. The determination method of soil particle content should be clearly defined in the characteristics of volcanic ash.
【學位授予單位】：沈陽農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S152
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本文編號：1396487