建筑結(jié)78課件講解

建筑結(jié)構(gòu)ArchitecturalStructures軸心受壓構(gòu)件承載力計(jì)算CalculationofAxialLoad-bearingCapacityforCompressionMembers4.3柱構(gòu)件設(shè)計(jì)ColumnDesign目錄

CONTENTS軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers1軸心受壓構(gòu)件截面復(fù)核CheckingofCross-sectionforAxiallyLoadedCompressionMembers2某百貨大樓塌陷Adepartmentstorecollapsed事故原因AccidentCause肆意改動(dòng)設(shè)計(jì)圖紙：四層寫(xiě)字樓改為五層商場(chǎng)；Arbitrarymodificationofdesigndrawings:convertingafour-storyofficebuildingintoafive-storyshoppingmall;更改立柱尺寸、偷工減料；Theunauthorizedalterationofpillardimensionsandtheuseofsubstandardmaterials;施工錯(cuò)誤：樓板鋼筋裝錯(cuò)位置；Constructionerror:Reinforcementbarsinthefloorslabinstalledatincorrectpositions;改變用途，暖氣設(shè)備增加重量；Theheatingequipmenthasgainedweightduetoachangeinitsintendeduse;超載：空調(diào)設(shè)備冷水機(jī)注水后超載。Overload:Thewaterchilleroftheairconditioningequipmentisoverloadedafterbeingfilledwithwater.事故原因AccidentCause12345事故原因AccidentCause800mm600mm無(wú)梁樓板結(jié)構(gòu)，豎向荷載靠柱子承擔(dān)；Itfeaturesaflat-slabstructurewithoutbeams,withtheverticalloadsprimarilysupportedbycolumns;柱的承載能力大大減低,為大樓倒塌埋下巨大隱患。Thusplantingahugesafetyhazardthateventuallyledtothecollapseofthebuilding.（16）（8）遵紀(jì)守法Observelawanddiscipline底線(xiàn)思維Bottom-linethinking工程倫理Engineeringethics思考：案例中立柱尺寸和鋼筋數(shù)量減少，其承載力降低，請(qǐng)大家思考承載力和什么因素有關(guān)？這些因素又如何在計(jì)算公式中體現(xiàn)呢？Thinking:Inthecase,whenthedimensionsofthecolumnandtheamountofreinforcementarereduced,itsbearingcapacitydecreases.Pleaseconsiderwhatfactorsarerelatedtothebearingcapacityofthecolumn?Andhowarethesefactorsreflectedinthecalculationformula?軸心受壓構(gòu)件承載力計(jì)算基本公式BasicFormulaforCalculatingtheBearingCapacityofAxiallyCompressedMembers《混凝土結(jié)構(gòu)設(shè)計(jì)規(guī)范》CodeforDesignofConcreteStructures

軸向壓力設(shè)計(jì)值Thedesignvalueforaxialcompressiveforce軸向受壓構(gòu)件的承載力Theload-bearingcapacityofanaxiallycompressedmember混凝土承載力Concretebearingcapacity鋼筋承載力ReinforcementbearingcapacityhbA'sA軸心受壓構(gòu)件承載力計(jì)算基本公式BasicFormulaforCalculatingtheBearingCapacityofAxiallyCompressedMembers

0.9是可靠度調(diào)整系數(shù)0.9representsthereliabilityadjustmentfactor.φ為鋼筋混凝土軸心受壓構(gòu)件的穩(wěn)定系數(shù)φdenotesthestabilitycoefficientofthereinforcedconcreteaxialcompressionmember.fc為混凝土抗壓強(qiáng)度設(shè)計(jì)值fcstandsforthedesignvalueofthecompressivestrengthoftheconcrete.軸心受壓構(gòu)件承載力計(jì)算基本公式BasicFormulaforCalculatingtheBearingCapacityofAxiallyCompressedMembers

A為構(gòu)件的截面面積，當(dāng)ρ>3%時(shí)，A改為（A-A's）Areferstothecross-sectionalareaofthemember，whenρ>3%,Aischangedto(A-A’s).fy′為鋼筋的抗壓強(qiáng)度設(shè)計(jì)值fy’isthedesignvalueofthecompressivestrengthofthereinforcingsteel.A′s為全部縱向受壓鋼筋的截面面積A’srepresentsthetotalcross-sectionalareaofallthelongitudinalcompressivereinforcementbars.軸心受壓構(gòu)件承載力計(jì)算基本公式BasicFormulaforCalculatingtheBearingCapacityofAxiallyCompressedMembers軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers軸心受壓承載力計(jì)算Calculatingthecompressivebearingcapacityforaxiallyloadedmembers截面設(shè)計(jì)Cross-sectiondesign截面復(fù)核Cross-sectionverification軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembersPARTONE軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers已知構(gòu)件尺寸b×h，軸向力設(shè)計(jì)值N，構(gòu)件計(jì)算長(zhǎng)度l0，材料強(qiáng)度等級(jí)fc及fy′,求：縱向受力鋼筋A(yù)s′Thedimensionsofthemember(b×h),thedesignvalueofaxialforceN,theeffectivelengthofthememberl0,andthestrengthgradesofthematerialfcandfy’areknown.ThetaskistodeterminetheareaAs’ofthelongitudinaltensilereinforcementsteel.01求穩(wěn)定系數(shù)φ

Calculatethestabilitycoefficientφ

計(jì)算鋼筋截面面積As’Calculatethecross-sectionalareaAs′ofthereinforcementsteel

驗(yàn)算配筋率ρ′Checkthereinforcementratioρ’01軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers

驗(yàn)算配筋率ρ′Checkthereinforcementratioρ’

選配鋼筋Selectingandmatchingreinforcingbars

01軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers02已知：構(gòu)件尺寸未知，軸向力設(shè)計(jì)值N，構(gòu)件計(jì)算長(zhǎng)度l0，材料強(qiáng)度等級(jí)fc

，fy’，求：縱筋截面面積As’。Given:Memberdimensionsareunspecified,designaxialforcevalueN,membercalculationlengthl0,materialstrengthgradefc,andyieldstrengthfy’,solvefor:thecross-sectionalareaAs’ofthelongitudinalreinforcingsteel.軸心受壓構(gòu)件截面設(shè)計(jì)DesignofCross-sectionforAxiallyLoadedCompressionMembers02假定φ=0.8~1.0，配筋率ρ′=1%Assumethestabilitycoefficientφtobewithintherangeof0.8to1.0,andsetthereinforcementratioρ′at1%.

確定b和hOnceAisdetermined,identifythewidth