本研究主要在探討由基質材料中夾雜著岩塊混合而成之併構岩的力學性質及行為。本研究設計一套單軸雙向壓實模具來壓製試體，以不同的二相組成材料，製作具有不同岩塊體積含量且基質材料乾密度相同之人造『巨觀等向性』併構岩試體，探討併構岩內部二相組成材料之體積含量與勁度關係對整體力學性質與行為的影響。此外，將前人對市售的岩石三軸室之改良方法加以改進，可同時解決鎖緊三軸室頂蓋時容易將訊號線剪斷與試驗過程中水份易沿著訊號線外漏的問題。 由試驗結果顯示，併構岩試體於單軸壓縮狀態下，由於受兩材料間軟弱界面的影響，整體的力學性質係由基質材料或界面性質來控制;當試體於三軸壓縮狀態下，由於圍壓的束制作用讓岩塊材料具有提升整體強、勁度的效果，此時整體的力學性質係由基質與岩塊材料共同控制。在不同岩塊體積含量併構岩力學性質部分，試體的凝聚力隨岩塊體積含量增加而降低;內摩擦角與材料參數m值則隨岩塊體積含量增加而提高。破壞模態觀察部分，併構岩的破壞模態與岩塊體積含量及圍壓大小有關，可將破壞模態分為軸向劈裂破壞、剪力滑動破壞、主剪力滑動面之共軛破壞及多組共軛破壞四種模態。理論模式分析部分，試體於單軸壓縮狀態下，低岩塊體積含量時較符合於假設二相材料為完全接合的預測模式，在高岩塊體積含量時，因兩材料間的軟弱界面數量增加，使二相複合材料的預測模式較不適用。試體於三軸壓縮狀態下，兩材料間的界面接合性質因圍束壓力而獲得改善，以微觀力學模式來預測併構岩的力學性質屬可行的方法。 The main purpose of this research is to study the mechanical properties and behaviors of bimrocks that composed of blocks in matrix. An uniaxial bi-directional compaction mold were designed to prepare the artificial bimrocks. By using different composite materials, the mechanical properties and behaviors with distinct block proportions and stiffnesses of the block and matrix are investigated. For the testing results, the mechanical properties of bimrock are controlled by matrix itself or the interface between block and matrix in uniaxial compression. With increasing confining pressures, the global mechanical properties and behaviors are controlled by both blocks and matrix in triaxial compression. Generally, increasing of block proportions decreased the cohesion and increased the internal friction angle and the material parameter m in Hoek-Brown criteria. Based on the experimental observation, the failure modes of the artificial bimrocks at different block proportions and confining pressures can be classified into four categories: axial splitting mode; shear fracture mode; conjugate shear mode with a main shear plane, and multiple conjugate shear planes mode. For theoretical prediction, the prediction models with assuming perfectly bonded interfaces in composite materials can fit the young’s modulus of the specimens at lower block proportions in uniaxial compression, but the prediction models can’t fit the data at higher block proportions. In triaxial compression, the micromechanics model can be used to predict the test data well.
