| 摘要: | 1999年集集地震至今，吸引中外學界熱烈投入各項研究，然而針對斷層帶岩石密度及孔隙率變化之探討卻異常的貧乏。本研究藉由TCDP台中大坑鑽井C井（深度1050-1280米包含四大斷層帶中圍岩與破裂帶取出之岩心），透過密集取樣並使用精密儀器，並參考A井實驗之經驗，更改取樣方法(加大切割取樣)及各項參數均取自同部位，以減少誤差。 ???賑膍s顯現，岩石密度隨著斷層變化有明顯之變化，即為密度由圍岩漸往斷層中心變小，孔隙率則隨之變大，熱傳導係數隨之變小，而熱擴散速率則隨之變大，熱傳導係數平均在2.5 W/m/K，隨著密度增大而增大，且砂岩的變化會比頁岩大。熱擴散速率平均在1.5 m m2/s則隨著密度增大而減小，但砂岩(1.72)比頁岩(1.13)大。推算出之比熱平均約700 J/kg/K，砂岩(625)為最小，砂頁岩(670)次之，最大為頁岩(820)。 密度與孔隙率試驗有高度的線性關係(R2=0.9)，並且樣本達到104個，證明本研究方法可行，砂岩之無孔隙密度為2.8 g/cm3，砂頁岩為2.84 g/cm3，頁岩為2.9 g/cm3，整體母岩之濕密度在2.6 g/cm3左右。孔隙率部分母岩都在10 %以下，頁岩(9.5 %)則比砂岩(7.5 %)大，砂頁岩互層(8.3 %)特性在砂岩與頁岩之間。 本實驗發現深度1178.7米處，擁有達到40% 的高孔隙率，且可以直接用手指輕易搓入，岩心未切割前，外觀上也顯現出鬆散，所以合理的懷疑此為921地震所引起之斷層帶。 After 1999 Chi-Chi earthquake, have many researcher study a lot of topics, but direct measurement the rock of changing of density and porosity of fault-zone rock are very rate. This research is with Taiwan Chelungpu-fault Drilling Project(TCDP) drilling C well of Takung (1050-1280 meters of depth include the drill core that is taken out of area with break of country rock in four major fault-zone ), use the precision type instrument through taking a sample intensively, and consult the experience of A well experiment , and every parameter is taken from with the position altering the sampling method ( bigger and cuts and takes a sample ), in order to reduce the error. Relieves and appear, the density of rock has obvious changes as the fault change, it is the density that is diminished to the fault centre gradually by the country rock, the porosity becomes great , heat-conductivity is diminished , but the speed of thermal diffusivity becomes large . Thermal-conductivity is average in 2.5W/m/K, increase as the density increases, and the change of the sandstone will be bigger than the shale. The thermal diffusivity is reduced averagely as the density increases, but the sandstone (1.72) is bigger than the shale (1.13). The heat capacity calculated invites 700 J/kg/K more equally, the sandstone (625) is minimum, and the sandstone and shale (670) take second place, most greatly the shale (820). The test of density and porosity to have height linear relations (R2 =0.9), And the sample reaches 104, prove this research approach is feasible, it is 2.8g/cm3 that sandstone has density of non-porosity, the sand and shale are 2.84g/cm3, the shale is 2.9g/cm3, the wet density of the whole host rock is in about 2.6 g/cm3. The whole porosity some host rock is under 10, the shale (9.5%) is bigger than the sandstone (7.5%), the characteristic of layer (8.3%) each other of sandstone and shale is between sandstone and shale. This experiment finds place of 1178.7 meters of depth, there is high porosity up to 40% , and can rub with the hands into easily with the finger directly , the drill core displays too loosely on the appearance before cutting, so rational this fault-zone caused by 921 earthquakes of suspicion. |
