[{"data":1,"prerenderedAt":62},["ShallowReactive",2],{"q-105170-arch_structure-5":3},{"question":4,"neighbors":27,"sameNumber":46,"prev":35,"next":38},{"id":5,"classKey":6,"session":7,"year":8,"subject":9,"number":10,"groupStem":11,"ownStem":12,"stem":12,"options":13,"answer":18,"answerKind":20,"answerS":11,"answerNote":11,"images":21,"explanation":23,"withheld":11,"deepChars":24,"freq":25,"indexable":26},"arch-105170-801-0102-005","architect","105170",105,"建築結構",5,null,"下圖梁中，B 為鉸，C 為滾支承，C 點的反力為何？ P B C A L L L",{"A":14,"B":15,"C":16,"D":17},"0","P\u002F2","P\u002F3","P",[19],"A","single",[22],"\u002Fimages\u002Farch-105170-801-0102-005.png","本題考點：含內鉸之複合梁（格柏梁）的反力求解，關鍵是先從內鉸處拆開，取不受載重的附屬段，用內鉸彎矩為零的條件求支承反力。\n【正解理由】依題圖所示，A 為固定端，集中載重 P 作用在距 A 為 L 的位置，B 為內鉸，距 A 為 2L，C 為滾支承，距 B 為 L。從內鉸 B 拆開，取 BC 段為自由體：BC 段上沒有任何載重，只有 B 點的內鉸力與 C 點的滾支承反力。對 B 點取彎矩平衡，C 點反力乘以 L 必須等於零，所以 C 點反力為 0；再由 BC 段垂直力平衡，B 點的內鉸剪力也是 0。也就是說，載重 P 全部由 AB 懸臂段與固定端 A 承擔，BC 段只是被「掛」在旁邊，不參與受力。故選 A。\n【逐項排除】\n(A) 正確。BC 段無載重，對內鉸 B 取彎矩，C 點反力 × L = 0，反力為 0。\n(B) 不正確。P\u002F2 是 C 點與另一支點平分載重時才會出現的量級，但本題載重作用在內鉸左側的懸臂段上，內鉸無法傳遞彎矩，BC 段上沒有外力，C 點分不到任何載重；正確值是 0。\n(C) 不正確。P\u002F3 同樣假設 C 點分擔了一部分載重。只要內鉸 B 不傳遞彎矩、BC 段上又沒有載重，C 點反力就必然為 0，與載重位置距離 C 點多遠無關。\n(D) 不正確。P 代表載重全部由 C 點承擔，方向相反：實際上載重全部由固定端 A 承擔，A 點垂直反力才是 P，C 點反力為 0。\n【演算步驟】\n取 BC 段，對內鉸 B 取彎矩：ΣM_B = R_C × L = 0 kN-m。\nBC 段上沒有載重，R_C = 0 kN。\nBC 段垂直力平衡：V_B + R_C = 0 kN，得內鉸剪力 V_B = 0 kN。\n【記憶點】格柏梁先拆內鉸，看哪一段沒有載重；沒有載重的附屬段，其支承反力與內鉸剪力都是零。",508,1,true,[28,31,34,37,40,43],{"number":29,"session":7,"stem":30},2,"下列何種建築物平面配置之耐震性能最佳？",{"number":32,"session":7,"stem":33},3,"高層結構在水平力作用下常有側向變形過大的問題，為減少其側向變形，採行下列何項措施效果…",{"number":35,"session":7,"stem":36},4,"拱結構系統抵抗水平反力之方法，下列何者錯誤？",{"number":38,"session":7,"stem":39},6,"在名建築「落水山莊」（Fallingwater）中，使樓版得以出挑於瀑布上方的梁結構…",{"number":41,"session":7,"stem":42},7,"進行建築物地基調查計畫時，依「建築物基礎構造設計規範」，調查深度至少應達到可據以確認…",{"number":44,"session":7,"stem":45},8,"下圖受軸力之桿件，ab 段的斷面積為 2A，bc 段的斷面積為 A，則 ab 段所受…",[47,50,53,56,59],{"number":10,"session":48,"stem":49},"114180","關於圓球薄殼結構，下列敘述何者錯誤？",{"number":10,"session":51,"stem":52},"113190","關於纜索結構（cable structures）的敘述，下列何者錯誤？",{"number":10,"session":54,"stem":55},"112190","關於材料波松比 ν（Poisson's ratio），下列何者錯誤？",{"number":10,"session":57,"stem":58},"111180","關於薄殼結構，下列敘述何者正確？",{"number":10,"session":60,"stem":61},"110180","關於隔震結構及制振結構之敘述，下列何者錯誤？",1791863213811]