2009-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/671469摘要：地殼和主要斷層的强度長久以一直是地球科學的挑戰和興趣，有關主要 斷層如加州聖安得列斯斷層(San Andreas fault)其強度較從實驗室量測代表 自然岩石強度的內摩擦係數為低的爭議一直都存在，因此如何瞭解強度控 制的力學機制，是解決此一問題的關鍵也是本研究之主要目的。本研究利 用顆粒體離散元素法研究楔形體臨界角模型(Critical-taper wedge)的基本力 學機制，考慮楔形體的幾何形態和組成物質的強度，測試控制摺皺逆衝帶 和增積楔形體的力學機制，並用地質資料約制數值模式的邊界條件和變形 型態。進一步，我們會將孔隙流體水壓應用於模型之中，評估同孔隙流 體水壓在臺灣西部摺皺逆衝帶和墨西哥灣對地殼强度和主要斷層強度的影 響。 同時，因地表下盲斷活動所引起的斷層擴展摺皺(fault-propagation folding)變形型態也是重要的課題，有助於瞭解地震災害潛勢。集集地震所 造成的車籠埔斷層活動造成一系列斷層擴展摺皺相關的單斜崖，這些因斷 層擴展摺皺所造成的地表破壞非常嚴重。雖然三角變形帶(Trishear)的運動 學理論可以解釋變形帶之型態，然而其基本力學機制仍有待進一步探究。 因此本研究中除了應用顆粒體離散元素研究地殼尺度的斷層強度外，也將 利用大地測量資料、差分合成孔徑雷達干涉技術和永久性散射體合成孔徑 雷達干涉技術所得到的地表變形資料，約制數值模式研究，完成褶皺逆衝 帶斷層擴展褶皺和地表盲斷層在同震或間震時期因斷層擴展所產生的變形 型態和力學機制。<br> Abstract: The strength of the crustal and major faults is the challenges and a great interest for Earth Sciences The debate of some major faults might be very weak relative to the friction measured from laboratory such as the San Andreas fault need to be further characterized by the of strength-controlling mechanisms. In our study, we aim at using discrete element modeling to understand the critical-taper wedge mechanics for the crustal and fault strength in active fold-and-thrust belts and accretionary wedges constrained by geological data. The wedge geometry and different strength of wedge materials are taken into account. Furthermore, we will incorporate the influence of pore-fluid pressure in our numerical modeling for evaluate the role of different pore-fluid pressure in different tectonic setting such as western Taiwan and Gulf of Mexico. In addition, the fault-propagation folds are generally associated with blind faults that are of great interest from an academic point of view. They have recently been recognized as extremely important for their seismic hazard potential. The Chi-Chi earthquake produced many monoclinal scarps by fault-propagation folding which caused great damage. The trishear kinematic model of fault-propagation folding appears to approximately represent the geometric development of some structures like monoclines, comparatively little is known of the mechanical controls on their development. Thus we construct a series of distinct-element models that consist of bounded assemblies of elastic particles that simulate the brittle deformation associated with fault-related folding over a rigid footwall. Here we attempt to predict the broad-scale features and basic characteristics of distributed deformation developed above blind contractional faults at depth. In addition, the fault activity will be modeled with the constrains from the surface deformation data of GPS, InSAR and PS-InSAR,離散元素法地殼和斷層强度孔隙流體水壓楔形體力學摺皺逆衝帶合成孔徑雷達差分干涉Discrete element modelingCrustal and fault strength,Pore-fluid pressure,Wedge mechanicsFold-and-thrust beltsPS-InSAR以離散元素法研究上部地殼的強度和力學機制(II)