|
碩士論文公告區 |
||
| 年度： | 93 | |
| 姓名： | 邱嘉裕(Chia-Yu Chiu) | |
| 論文題目(中)： | 以敲擊回音法探討壓力及剪力波速與土壤夯實狀態之初步研究 | |
| 論文題目(英)： | A preliminary study of exploring the relationship between P- and S-speeds measured by impact-echo method and the compacting condition of soil | |
| 摘要(中)： | ||
| 「夯實」品質決定填方工程之品質，其目的在於（1）增加土壤的抗剪強度，以提高基礎的承載力，填築邊坡的穩定性，（2）減小壓縮性（壓密沉陷）降低未來之沉陷量，可減少或防止有害沉陷之情形發生，（3）降低滲透性，增強抗土壤抗滲能力。 本論文研究的目的在探討使用敲擊回音法來檢測壓力及剪力波速與土壤夯實狀態，包括壓力及剪力波速與土壤密度、含水量及加州承載比間之關係，期能獲得相關研究成果，以評估日後是否有可取代填方工程中耗力費時之工地密度充砂法或具有危險性之核子工地密度及含水量試驗之可能性。 本論文主要是採用寶山第二水庫計畫—大壩工程之特別輾壓材料、心層及殼層填方土壤材料，該土壤材料彼此間之工程性質迥異，進行壓力及剪力波速與土壤密度、含水量及加州承載比試驗，期能尋求出其彼此間之關係。 本論文研究發現：(1) 當夯實試體之含水量在乾側（即含水量低於最佳含水量）時，隨著含水量逐漸增加，土壤夯實乾密度逐漸增大，壓力波速及剪力波速亦均隨之增快，夯實乾密度越大則波速越快，及至趨近最佳含水量前約幾﹪之含水量時，其壓力波速及剪力波速均隨著含水量逐漸增加而大幅降低。(2) 在固定夯實能量時隨著夯實乾密度逐漸增加，壓力波速亦隨之大幅增加，至某一特定土壤夯實乾密度時，產生急遽下降之情形(3) 在固定含水量狀況下隨著夯實乾密度逐漸增加，兩種土壤之壓力波速及剪力波速亦隨之增加。(4) 波速與加州承載比關係中，顯示出波速會隨著加州承載比值的上升而呈現增加的趨勢。(5) 彈性模數隨著加州承載比增加而增加，有成正比的趨勢，將來實際應用時可利用E值估計承載力。 |
||
| 摘要(英)： | ||
| The quality of “compaction” is a conclusive factor to the quality of an embankment project. Compaction of an embankment aims at (1) to increase the shearing strength for improving the bearing capacity of foundation and/or the stability of side slope of embankment, (2) to reduce the compressibility (consolidation settlement) for decreasing future settlement, on account of minimizing or preventing occurrence of hazardous settlement，(3) to decrease the permeability for improving the imperviousness. The purpose of study is to examine a method of measuring the velocities of P-wave and S-wave by an Impact-Echo method to evaluate the compacted conditions of the embankment, including the relationship between the velocities of P-wave and S-wave and the density, water content, and CBR, on account of evaluating the possibility of replacing the labor and time consuming Sand-Cone method or the dangerous nuclear method with the Impact-Echo method in measuring field densities and moisture contents. The materials used in the study of this thesis are the contact clay, and the core and shell materials to be placed in the PaoShan Second Reservoir Project. The engineering properties of these materials are quite different mutually. Performing P-wave and S-wave velocity measurement, and tests of density, moisture content and CBR, in expectation of being able to find out some relationship among these test data. From this study, the following have been found：(1) As the compacted dry density of the embankment increases gradually, the velocities of P-wave and S-wave also increase gradually. Higher the compacted dry density, faster the P-wave and S-wave velocities become. Up until the compacted dry density approaching the maximum, the wave velocities start to decrease in reverse. When the compacted dry density begins to decrease, the wave velocities decrease significantly； (2) P-wave and S-wave velocities decrease sharply as the water content increase gradually；(3) Under a fixed water content, following gradual increase of compacted dry density, the p- and s- velocities of the embankment increase. However, for overly high water content, the wave velocities become unstable and the relationship between the wave velocities and the compacted dry density is indistinct；(4) the relationship between the wave velocities and the CBR indicates that the wave velocities have a tendency to increase following the CBR value increase；(5) The CBR value has the tendency of increase proportionally with the elastic modulus obtained from the wet density, and speeds of P and S waves. Thus, with correct measurement of P and S-wave, it is possible to evaluate the bearing capacity of soil in field via the calculated elastic modulus. |
||
| 檔案： | 沒有相關檔案 | |
| 相關連結： | http://ethesys.lib.cyut.edu.tw/ETD-db/ETD-search-c/view_etd?URN=etd-0818105-043523 | |