[{"data":1,"prerenderedAt":63},["ShallowReactive",2],{"q-114180-arch_structure-5":3},{"question":4,"neighbors":28,"sameNumber":47,"prev":36,"next":39},{"id":5,"classKey":6,"session":7,"year":8,"subject":9,"number":10,"groupStem":11,"ownStem":12,"stem":12,"options":13,"answer":18,"answerKind":21,"answerS":19,"answerNote":22,"images":23,"explanation":24,"withheld":11,"deepChars":25,"freq":26,"indexable":27},"arch-114180-801-0102-005","architect","114180",114,"建築結構",5,null,"關於圓球薄殼結構，下列敘述何者錯誤？",{"A":14,"B":15,"C":16,"D":17},"圓頂重量過大時，會造成圓頂底部向外變形過大而開裂，此時必須加設鋼箍作為壓力環","在對稱自重作用下，經度纖維均受壓應力","在對稱自重作用下，天頂角大於 52°範圍，緯度纖維均受張應力","為不可展開薄殼",[19,20],"A","C","multi","第5題答Ａ或Ｃ或ＡＣ者均給分",[],"本題考點：圓球薄殼（圓頂）在對稱自重下的薄膜內力分布——經向（經度）力與緯向（環向）力的正負、底部環梁的受力型式，以及薄殼的可展開性。\n【正解理由】圓頂在自重作用下，經向纖維由頂部一路受壓傳到底部；緯向（環向）纖維在頂部附近受壓，越往下天頂角越大，環向壓力逐漸減小，約在天頂角 52° 附近由壓轉張，再往下就成為張力。圓頂底部有向外擴張的趨勢，抵抗向外變形的鋼箍（環梁）被撐開而受拉，應稱為張力環（拉力環）；(A) 寫成「壓力環」，構件受力型式錯誤。考選部公告本題答 A 或 C 或 AC 者均給分。故選 A 或 C。\n【逐項排除】\n(A) 敘述錯誤。圓頂底部向外變形，表示底緣圓周有被撐大的傾向，抵抗它的鋼箍被拉長，承受拉力，應為「張力環」；「壓力環」是用在圓頂頂部開口（天窗）周邊，那裡的經向壓力向內集中，環梁受擠壓。選項把底部的張力環錯稱為壓力環。\n(B) 敘述正確。對稱自重下，每一圈緯線以上的殼體重量都由經向纖維向下傳遞，經向薄膜力全區均為壓力，這也是圓頂可用磚石、混凝土等抗壓材料興建的原因。\n(C) 依薄膜理論，緯向力約在天頂角 52° 附近由壓轉張，天頂角大於此值的下部殼體，緯度纖維受張應力，選項描述與此分布趨勢相符。考選部公告本題答 C 者亦給分。\n(D) 敘述正確。圓球面在兩個方向都有同號曲率，無法在不撕裂、不擠壓材料的情況下攤平成平面，屬不可展開曲面；可展開的是圓柱面、圓錐面這類單向曲率的曲面。\n【記憶點】圓頂自重：經向全受壓；環向上壓下張，分界約在天頂角 52°；底部環梁是張力環，頂部開口環梁才是壓力環。",463,1,true,[29,32,35,38,41,44],{"number":30,"session":7,"stem":31},2,"下列有關混凝土性質的敘述，何者錯誤？",{"number":33,"session":7,"stem":34},3,"如圖所示，x 軸為作用力的反覆加載週期數目（N），y 軸為鋼所承受的應力（MPa）大…",{"number":36,"session":7,"stem":37},4,"一長度為 2 m 圓棒，直徑為 30 mm，彈性模數為 70 GPa，波松比（Poi…",{"number":39,"session":7,"stem":40},6,"關於薄膜結構，下列敘述何者正確？",{"number":42,"session":7,"stem":43},7,"下列何種結構系統較不適用於超過 50 公尺之高層建築？",{"number":45,"session":7,"stem":46},8,"有關高層建築結構系統與設計，下列敘述何者錯誤？①高層建築於設計風力下之層間位移角，不…",[48,51,54,57,60],{"number":10,"session":49,"stem":50},"113190","關於纜索結構（cable structures）的敘述，下列何者錯誤？",{"number":10,"session":52,"stem":53},"112190","關於材料波松比 ν（Poisson's ratio），下列何者錯誤？",{"number":10,"session":55,"stem":56},"111180","關於薄殼結構，下列敘述何者正確？",{"number":10,"session":58,"stem":59},"110180","關於隔震結構及制振結構之敘述，下列何者錯誤？",{"number":10,"session":61,"stem":62},"109180","有關建築物基本振動週期之敘述，下列何者錯誤？",1791863195354]