地形反映了地殼抬昇與侵蝕作用，長期以來，源於完整岩石強度很高，因此切蝕被認為是型塑地形的最重要因素。近年來研究卻發現，大尺度岩體強度將遠低於室內岩石實驗獲得之強度，因此，岩體強度極可能是限制地形高差的另外一個重要因素。坡度與坡高常被用於束限岩體強度參數，不論是地球或火星都有一些研究案例，本計畫將建立一系列邊坡反應曲線，為考慮強度之非線性，本計畫將引入Hoek-Brown 破壞準則，同時，邊坡反應曲線將反應孔隙水壓以及地震力之影響。為驗證模式，大量現地調查以及實驗室工作將全面展開，以獲得地質強度指標(GSI)以及完整岩石單壓強度。另外，本計畫亦將進行滲流分析，以獲得邊坡穩定分析所需孔隙水壓。藉由邊坡反應曲線，岩體強度即可反衍產生。另一方面，加積楔模型可充分連結褶皺逆衝帶形狀與加積楔以及滑脫面強度，如果加積楔強度可反衍自地形(如前所述)，則滑脫面強度以及地殼內部流體壓力即有可能以加積楔模型束限之，本計畫將利用低速-高速旋剪儀設備，進行摩擦係數量測，並配合鑽井液壓量測值，以驗證此一構想。本計畫為四年期計畫，第一年與第二年將發展考慮非線性破壞準則之邊坡反應曲線與加積楔模型，配合第一年即開始持續展開(為期四年)的大量現地調查、實驗室試驗以及數值模擬工作，本計畫預期將探討下列科學議題：(1)強度如何束限地形？(2)孔隙水壓對地形有何影響？(3)古地震如何影響地形演育？(4)有沒有可能利用增積楔模型反衍地殼中流體超靜壓？最後，本計畫將點出地殼材料非線性與尺度效應如何影響褶皺逆衝帶地表地形與地下形貌。 Relief is a fundamental landscape reflecting the influence of uplift and erosion. Contrary to the traditional concept that the relief is dominated by incision, recent research indicated that the landscape-scale material strength play an important role on the landform process. However, it is difficult to obtain a representative strength parameters based on laboratory rock tests. Slope height and slope angle were frequently used to infer the strength of rock mass (both for earth and Mars). In this project, a series of slope response curves will be proposed to constrain the rock mass strength. Non-linear Hoek-Brown failure criterion will be incorporated into the proposed model where the linear Mohr-Coulomb failure envelop seems oversimplified. Extensively field works (measure the geological strength index; GSI), laboratory tests (measure the uniaxial compressive strength) and numerical simulations (seepage analysis) will be conducted to build the non-linear model which the influence of earthquake and pore pressure is considered. Consequently, the strength of rock mass could be inferred from the topography. On the other hand, critical-taper wedge theory explains the first-order geometry of fold and thrust belts as a function of the internal strength of the wedge of deforming material and the strength of the basal detachment. If the internal strength of the wedge could be inferred from topography as aforementioned, it is anticipated that the long term frictional coefficient of the detachment and overpressure distributed in the crust could be constrained. A low to high velocity rotary shear apparatus is utilized to measure the “drained” frictional coefficient. Together with the pore pressure measured in CPC oil well, this ideal could be validated. Derivation of the non-linear models including the slope response curves and critical-taper wedge model is the main target for the first year of this four years project. Based on the extensive field, laboratory works and numerical simulation lasting four years, the scientific issues dressed as follows will be carefully explored. (1) How the strength limit the relief? (2) What is the role of pore pressure on topography? (3) Would it be possible to evaluate the influence of paleo-earthquakes on topography, quantitatively? (4) How to constraint the crust pore pressure, which dominating the deformation and failure of crust, in an efficient way? Following this line, the effects of nonlinearity and scale (from shallow to deep) on crust strength will be highlighted. 研究期間：10008 ~ 10107
