外文翻譯--抗震設(shè)計(jì)的發(fā)展

1、<p><b>　　附錄一：</b></p><p><b>　　抗震設(shè)計(jì)的發(fā)展</b></p><p>　　摘要： 1 抗震設(shè)計(jì)思路發(fā)展歷程；2 現(xiàn)代抗震設(shè)計(jì)思路；3 保證結(jié)構(gòu)延性能力的抗震措施； 4 常用抗震分析方法</p><p>　　關(guān)鍵詞： 結(jié)構(gòu)設(shè)計(jì) 抗震</p><p>

2、;　　1.抗震設(shè)計(jì)思路發(fā)展歷程</p><p>　　隨著建筑結(jié)構(gòu)抗震相關(guān)理論研究的不斷發(fā)展，結(jié)構(gòu)抗震設(shè)計(jì)思路也經(jīng)歷了一系列的變化。 最初，在未考慮結(jié)構(gòu)彈性動(dòng)力特征，也無(wú)詳細(xì)的地震作用記錄統(tǒng)計(jì)資料的條件下，經(jīng)驗(yàn)性的取一個(gè)地震水平作用（0.1 倍自重）用于結(jié)構(gòu)設(shè)計(jì)。隨著地面運(yùn)動(dòng)記錄的不斷豐富，人們通過(guò)單自由度體系的彈性反應(yīng)譜，第一次從宏觀上看到地震對(duì)彈性結(jié)構(gòu)引起的反應(yīng)隨結(jié)構(gòu)周期和阻尼比變化的總體趨勢(shì)，揭示了結(jié)構(gòu)在地震

3、地面運(yùn)動(dòng)的隨機(jī)激勵(lì)下的強(qiáng)迫振動(dòng)動(dòng)力特征。但同時(shí)也發(fā)現(xiàn)一個(gè)無(wú)法解釋的矛盾，當(dāng)時(shí)規(guī)范所取的設(shè)計(jì)用地面運(yùn)動(dòng)加速度明顯小于按彈性反應(yīng)譜得出的作用于結(jié)構(gòu)上的地面運(yùn)動(dòng)加速度，這些結(jié)構(gòu)大多數(shù)卻并未出現(xiàn)嚴(yán)重?fù)p壞和倒塌。后來(lái)隨著對(duì)結(jié)構(gòu)非線性性能的不斷研究，人們發(fā)現(xiàn)設(shè)計(jì)結(jié)構(gòu)時(shí)取的地震作用只是賦予結(jié)構(gòu)一個(gè)基本屈服承載力，當(dāng)發(fā)生更大地震時(shí)，結(jié)構(gòu)將在一系列控制部位進(jìn)入屈服后非彈性變形狀態(tài)，并靠其屈服后的非彈性變形能力來(lái)經(jīng)受地震作用。由此，也逐漸形成了使結(jié)構(gòu)在一定

4、水平的地震作用下進(jìn)入屈服，并達(dá)到足夠的屈服后非彈性變形狀態(tài)來(lái)耗散能量的現(xiàn)代抗震設(shè)計(jì)理論。 由以上可以看出，結(jié)構(gòu)抗震設(shè)計(jì)思路經(jīng)歷了從彈性到非線性，從基于經(jīng)驗(yàn)到基于非線性理論，從單純保證結(jié)構(gòu)承載能力到</p><p>　　2.現(xiàn)代抗震設(shè)計(jì)思路</p><p>　　在當(dāng)前抗震理論下形成的現(xiàn)代抗震設(shè)計(jì)思路，其主要內(nèi)容是：</p><p>　　(1） 合理選擇確定結(jié)構(gòu)屈服水準(zhǔn)

5、的地震作用。一般先以具有統(tǒng)計(jì)意義的地面峰值加速度作為該地區(qū)地震強(qiáng)弱標(biāo)志值（即中震的），再以不同的R（地震力降低系數(shù)）得到不同的設(shè)計(jì)用地面運(yùn)動(dòng)加速度（即小震的）來(lái)進(jìn)行結(jié)構(gòu)的強(qiáng)度設(shè)計(jì)，從而確定了結(jié)構(gòu)的屈服水準(zhǔn)。</p><p>　　(2） 制定有效的抗震措施使結(jié)構(gòu)確實(shí)具備設(shè)計(jì)時(shí)采用的R所對(duì)應(yīng)的延性能力。其中主要包括內(nèi)力調(diào)整措施（強(qiáng)柱弱梁、強(qiáng)剪弱彎）和抗震構(gòu)造措施。</p><p>　　現(xiàn)代抗震

6、設(shè)計(jì)理念是基于對(duì)結(jié)構(gòu)非彈性性能的研究上建立起來(lái)的，其核心是關(guān)系，關(guān)系主要指在不同滯回規(guī)律和地面運(yùn)動(dòng)特征下，結(jié)構(gòu)的屈服水準(zhǔn)與自振周期以及最大非彈性動(dòng)力反應(yīng)間的關(guān)系。其中R為彈塑性反應(yīng)地震力降低系數(shù)，簡(jiǎn)稱(chēng)地震力降低系數(shù)；而為最大非彈性反應(yīng)位移與屈服位移之比，稱(chēng)為位移延性系數(shù)；T則為按彈性剛度求得的結(jié)構(gòu)自振周期。</p><p>　　在滯回曲線為理想彈塑性及彈性剛度始終不變的前提下，通過(guò)對(duì)不同周期，不同屈服水準(zhǔn)的非彈性

7、單自由度體系做動(dòng)力分析，得到了有關(guān)彈塑性反應(yīng)下最大位移的規(guī)律：對(duì)T大于1.0秒的體系適用 “等位移法則”即非彈性反應(yīng)下的最大位移總等于同一地面運(yùn)動(dòng)輸入下的彈性反應(yīng)最大位移。對(duì)于T在0.12－0.5秒之間的結(jié)構(gòu)，適用“等能量法則”即非彈性反應(yīng)下的彈塑性變形能等于同一地震地面運(yùn)動(dòng)輸入下的彈性變形能。當(dāng)“等能量原則”適用時(shí)，隨著R的增大，位移延性需求的增長(zhǎng)速度比“等位移原則”下按與R相同的比例增長(zhǎng)更快。由以上規(guī)律我們可以看出，如果以結(jié)構(gòu)彈性反

8、應(yīng)為準(zhǔn)，把結(jié)構(gòu)用來(lái)做承載能力設(shè)計(jì)的地震作用取的越低，即R越大，則結(jié)構(gòu)在與彈性反應(yīng)時(shí)相同的地震作用下達(dá)到的非彈性位移就越大，位移延性需求就越高。這意味著結(jié)構(gòu)必須具有更高的塑性變形能力。規(guī)律初步揭示出不同彈性周期的結(jié)構(gòu)，當(dāng)其彈塑性屈服水準(zhǔn)取值大小不同時(shí)，在同一地面運(yùn)動(dòng)輸入下屈服水準(zhǔn)與所達(dá)到的最大非彈性位移之間的關(guān)系。也揭示出了延性能力和塑性耗能能力是屈服水準(zhǔn)不高的結(jié)構(gòu)在較大地震引起的非彈性動(dòng)力反應(yīng)中不致發(fā)生嚴(yán)重?fù)p壞和倒塌的主要原因。讓人們認(rèn)

9、識(shí)到延性在抗震設(shè)計(jì)中的重要性。</p><p>　　之所以存在上訴的規(guī)律，我們應(yīng)該注意到鋼筋混凝土結(jié)構(gòu)的一些相關(guān)特性。首先，通過(guò)人為措施可以使結(jié)構(gòu)具有一定的延性，即結(jié)構(gòu)在外部作用下，可以發(fā)生足夠的非線性變形，而又維持承載力的屬性。這樣就可以保證結(jié)構(gòu)在進(jìn)入較大非線性變形時(shí)，不會(huì)出現(xiàn)因強(qiáng)度急劇下降而導(dǎo)致的嚴(yán)重破壞和倒塌，從而使結(jié)構(gòu)在非線性變形狀態(tài)下耗能成為可能。其次，作為非線彈性材料的鋼筋混凝土結(jié)構(gòu)，在一定的外力作用

10、下，結(jié)構(gòu)將從彈性進(jìn)入非彈性狀態(tài)。在非彈性變形過(guò)程中，外力做功全部變?yōu)闊崮埽魅肟諝庵泻纳⒌?。我們可以進(jìn)一步以單質(zhì)點(diǎn)體系的無(wú)阻尼振動(dòng)來(lái)分析，在彈性范圍振動(dòng)時(shí)，慣性力與彈性恢復(fù)力總處于動(dòng)態(tài)平衡狀態(tài)，體系能量在動(dòng)能、勢(shì)能間不停轉(zhuǎn)換，但總量保持不變。如果某次振動(dòng)過(guò)大，體系進(jìn)入屈服后狀態(tài)，則體系在平衡位置的動(dòng)能將在最大位移處轉(zhuǎn)化為彈性勢(shì)能和塑性變形能兩部分，其中，塑性變性能將耗散掉，從而減小了體系總的能量。由此我們可以想到，在地震往復(fù)作用下，結(jié)

11、構(gòu)在振動(dòng)過(guò)程中，如果進(jìn)入屈服后狀態(tài)，將通過(guò)塑性變性能耗散掉部分地震輸給結(jié)構(gòu)的累積能量，從而減小地震反應(yīng)。同時(shí)，實(shí)際結(jié)構(gòu)存在的阻尼也會(huì)進(jìn)一步耗散能量，減小地震反應(yīng)。此外，結(jié)構(gòu)進(jìn)入非彈性狀態(tài)后，其側(cè)向</p><p>　　隨著對(duì)規(guī)律認(rèn)識(shí)的深入，這一規(guī)律已被各國(guó)規(guī)范所接受。在抗震設(shè)計(jì)時(shí)，對(duì)在同一烈度區(qū)的同一類(lèi)結(jié)構(gòu)，可以根據(jù)情況取用不同的R，也就是不同的用于強(qiáng)度設(shè)計(jì)的地震作用。當(dāng)R取值較大，即用于設(shè)計(jì)的地震作用較小時(shí)，對(duì)

12、結(jié)構(gòu)的延性要求就越嚴(yán)；反之，當(dāng)R取值較小，即用于設(shè)計(jì)的地震作用較大時(shí)，對(duì)結(jié)構(gòu)的延性要求就可放松。</p><p>　　目前，逐步形成了一套“多層次，多水準(zhǔn)性態(tài)控制目標(biāo)”的抗震理念。這一理念主要含義為：工程師應(yīng)該選擇合適的形態(tài)水準(zhǔn)和地震荷載進(jìn)行結(jié)構(gòu)設(shè)計(jì)。建筑物的性態(tài)是由結(jié)構(gòu)的性態(tài)，非結(jié)構(gòu)構(gòu)件和體系的性態(tài)以及建筑物內(nèi)容物性態(tài)的組合。目前性態(tài)水準(zhǔn)一般分為：損傷出現(xiàn)、正常運(yùn)作、能繼續(xù)居住、可修復(fù)的、生命安全、倒塌。性態(tài)目

13、標(biāo)指建筑物在一定程度的地震作用下對(duì)所期望的性態(tài)水準(zhǔn)的表述。對(duì)建筑抗震設(shè)計(jì)應(yīng)采用多重性態(tài)目標(biāo)，對(duì)一般結(jié)構(gòu)、必要結(jié)構(gòu)、對(duì)安全起控制作用的結(jié)構(gòu)分別建議了相應(yīng)的性態(tài)目標(biāo)――基本目標(biāo)（常遇地震下完全正常運(yùn)作，少遇地震下正常運(yùn)作，罕遇地震下保證生命安全，極罕遇地震下接近倒塌）、必要目標(biāo)（少于地震下完全正常運(yùn)作，罕遇地震下正常運(yùn)作，極罕遇地震下保證生命安全）、對(duì)安全其控制作用的目標(biāo)（罕遇地震下完全正常運(yùn)作，極罕遇地震下正常運(yùn)作）。對(duì)重要性不同的建筑，

14、如協(xié)助進(jìn)行災(zāi)害恢復(fù)行動(dòng)的醫(yī)院等建筑，應(yīng)該按較高的性態(tài)目標(biāo)設(shè)計(jì)，此外，也可以針對(duì)甲方對(duì)建筑提出的不同抗震要求，選擇不同的性態(tài)目標(biāo)。</p><p>　　3．保證結(jié)構(gòu)延性能力的抗震措施</p><p>　　合理選擇了結(jié)構(gòu)的屈服水準(zhǔn)和延性要求后，就需要通過(guò)抗震措施來(lái)保證結(jié)構(gòu)確實(shí)具有所需的延性能力，從而保證結(jié)構(gòu)在中震、大震下實(shí)現(xiàn)抗震設(shè)防目標(biāo)。系統(tǒng)的抗震措施包括以下幾個(gè)方面內(nèi)容：</p>

15、<p>　　（1）“強(qiáng)柱弱梁”：人為增大柱相對(duì)于梁的抗彎能力，使鋼筋混凝土框架在大震下，梁端塑性鉸出現(xiàn)較早，在達(dá)到最大非線性位移時(shí)塑性轉(zhuǎn)動(dòng)較大；而柱端塑性鉸出現(xiàn)較晚，在達(dá)到最大非線性位移時(shí)塑性轉(zhuǎn)動(dòng)較小，甚至根本不出現(xiàn)塑性鉸。從而保證框架具有一個(gè)較為穩(wěn)定的塑性耗能機(jī)構(gòu)和較大的塑性耗能能力。</p><p>　?。?）“強(qiáng)剪弱彎”：剪切破壞基本上沒(méi)有延性，一旦某部位發(fā)生剪切破壞，該部位就將徹底退出結(jié)構(gòu)抗

16、震能力，對(duì)于柱端的剪切破壞還可能導(dǎo)致結(jié)構(gòu)的局部或整體倒塌。因此可以人為增大柱端、梁端、節(jié)點(diǎn)的組合剪力值，使結(jié)構(gòu)能在大震下的交替非彈性變形中其任何構(gòu)件都不會(huì)先發(fā)生剪切破壞。</p><p>　?。?） 抗震構(gòu)造措施：通過(guò)抗震構(gòu)造措施來(lái)保證形成塑性鉸的部位具有足夠的塑性變形能力和塑性耗能能力，同時(shí)保證結(jié)構(gòu)的整體性。</p><p>　　這一系統(tǒng)的抗震措施理念已被世界各國(guó)所接受，但是對(duì)于耗能機(jī)構(gòu)

17、卻出現(xiàn)了以新西蘭和美國(guó)為代表的兩種不完全相同的思路。首先，這兩種思路都是以?xún)?yōu)先引導(dǎo)梁端出塑性鉸為前提。</p><p>　　抗震研究者認(rèn)為耗能機(jī)構(gòu)宜采用符合塑性力學(xué)中的“理想梁鉸機(jī)構(gòu)”，即梁端全部形成塑性鉸，同時(shí)底層柱底也都形成塑性鉸的“全結(jié)構(gòu)塑性機(jī)構(gòu)”。其具體做法是通過(guò)結(jié)構(gòu)分析得到各構(gòu)件組合內(nèi)力值后，對(duì)梁端截面就按組合彎矩進(jìn)行截面設(shè)計(jì)；而對(duì)除底層柱底以外的柱截面，則用人為增大了以后的組合彎矩和組合軸力進(jìn)行設(shè)計(jì)；

18、對(duì)底層柱底截面則用增大幅度較小的組合彎矩和組合軸力進(jìn)行截面設(shè)計(jì)。通過(guò)這一做法實(shí)現(xiàn)在大震下的較大塑性變形中，梁端塑性鉸形成的較為普遍，底層柱底塑性鉸出現(xiàn)遲于梁端塑性鉸，而其余所有的柱截面不出現(xiàn)塑性鉸，最終形成“理想梁鉸機(jī)構(gòu)”。為此，這種方法就必須取足夠大的柱端彎矩增強(qiáng)系數(shù)。</p><p>　　另一方則認(rèn)為取的柱彎矩增強(qiáng)系數(shù)過(guò)大，根據(jù)經(jīng)驗(yàn)取了較小的柱彎矩增強(qiáng)系數(shù)，這一做法使結(jié)構(gòu)在大震引起的非彈性變形過(guò)程中，梁端塑性

19、鉸形成較早，柱端塑性鉸形成的相對(duì)較遲，梁端塑性鉸形成的較普遍，柱端塑性鉸形成的相對(duì)少一些，從而形成“梁柱塑性鉸機(jī)構(gòu)”。</p><p>　　“理想梁鉸機(jī)構(gòu)”抗震措施的好處在于“理想梁鉸機(jī)構(gòu)”完全利用了延性和塑性耗能能力較好的梁端塑性鉸來(lái)實(shí)現(xiàn)框架延性和耗散地震能量，同時(shí)因?yàn)槌讓又淄獾钠渌瞬怀霈F(xiàn)塑性鉸，也就不必再對(duì)這些柱端加更多的箍筋。但是這種思路過(guò)于受塑性力學(xué)形成理想機(jī)構(gòu)概念的制約，總認(rèn)為底層柱底應(yīng)該形成塑

20、性鉸，這樣就對(duì)底層柱底提出了較嚴(yán)格的軸壓比要求，同時(shí)還要用足夠多的箍筋來(lái)使柱底截面具有所需的延性，此外，底層柱底如果延性不夠發(fā)生破壞很容易導(dǎo)致結(jié)構(gòu)整體倒塌。這些不利因素使該方法喪失了很大的優(yōu)勢(shì)。</p><p>　　因此不需要被塑性力學(xué)的機(jī)構(gòu)概念所限制，只要能在大震下實(shí)現(xiàn)以下的塑性耗能機(jī)構(gòu)，就能保證抗震設(shè)計(jì)的基本要求：</p><p>　　(1) 以梁端塑性鉸耗能為主；</p>

21、<p>　　(2) 不限制柱端塑性鉸出現(xiàn)（包括底層柱底），但是通過(guò)適當(dāng)增強(qiáng)柱端抗彎能力的方法使它在大震下的塑性轉(zhuǎn)動(dòng)離其塑性轉(zhuǎn)動(dòng)能力有足夠裕量。</p><p>　　(3) 同層各柱上下端不同時(shí)處于塑性變形狀態(tài)。</p><p>　　我國(guó)的抗震措施中對(duì)耗能機(jī)構(gòu)的考慮也基本遵循了這一思路，采用了“梁柱塑性鉸機(jī)構(gòu)”模式。</p><p>　　抗震設(shè)計(jì)中我們?yōu)?/p>

22、了避免沒(méi)有延性的剪切破壞的發(fā)生，采取了“強(qiáng)剪弱彎”的措施來(lái)處理構(gòu)件受彎能力與受剪能力的關(guān)系問(wèn)題。值得注意的是，與非抗震抗剪破壞相比，地震作用下的剪切破壞是不同的。以梁構(gòu)件為例，在較大地震作用下，梁端形成交叉斜裂縫區(qū)，該區(qū)混凝土受斜裂縫分割，形成若干個(gè)菱形塊體，而且破碎會(huì)隨著延性增長(zhǎng)而加劇。由于交叉斜裂縫與塑性鉸區(qū)基本重合，垂直和斜裂縫寬度都會(huì)隨延性而增大?？拐鹣赂鶕?jù)梁端的受力特征，正剪力總是大于負(fù)剪力，正剪力作用下的剪壓區(qū)一般位于梁下部

23、，但由于地震的往復(fù)作用，梁底的混凝土保護(hù)層可能已經(jīng)剝落，從而削弱了混凝土剪壓區(qū)的抗剪能力；交叉斜裂縫寬度比非抗震情況大，以及斜裂縫反復(fù)開(kāi)閉，混凝土破碎更嚴(yán)重，從而使斜裂縫界面中的骨料咬合效應(yīng)退化；混凝土保護(hù)層剝落和裂縫的加寬又會(huì)使縱筋的銷(xiāo)栓作用有一定退化?？梢?jiàn)，地震作用下，混凝土抗剪能力嚴(yán)重退化，但是試驗(yàn)發(fā)現(xiàn)箍筋的抗剪能力仍可以維持。</p><p>　　當(dāng)?shù)卣鹱饔迷絹?lái)越小時(shí)，梁端可能不出現(xiàn)雙向斜裂縫，而出現(xiàn)單向

24、斜裂縫，裂縫寬度發(fā)育也從大于非抗震情況到接近非抗震情況，抗剪環(huán)境越來(lái)越有利。此外，抗震抗剪要求結(jié)構(gòu)構(gòu)件應(yīng)在大震下預(yù)計(jì)達(dá)到的非彈性變形狀態(tài)之前不發(fā)生剪切破壞。因?yàn)榭蚣芗羟衅茐目偸前l(fā)生在梁端塑性鉸區(qū)，這就不僅要求在梁端形成塑性鉸前不發(fā)生剪切破壞，而且抗剪能力還要維持到塑性鉸的塑性轉(zhuǎn)動(dòng)達(dá)到大震所要求的程度，這就需要更多的箍筋。同時(shí)，在梁端塑性變形過(guò)程中作用剪力并沒(méi)有明顯增大，也進(jìn)一步說(shuō)明這里增加的箍筋不是用來(lái)增大抗剪強(qiáng)度，而是為了提高構(gòu)件在發(fā)

25、生剪切破壞時(shí)所達(dá)的延性。</p><p>　　綜上所述，與非抗震抗剪相比，抗震抗剪性能是不同的，其性能與剪力作用環(huán)境，塑性區(qū)延性要求大小有關(guān)。我們可以采取以下公式來(lái)考慮抗震抗剪的強(qiáng)度公式：</p><p>　　其中為混凝土抗剪能力，為箍筋抗剪能力，為由于地震作用導(dǎo)致的混凝土抗剪能力下降的折減系數(shù)，且隨著剪力作用環(huán)境、延性要求而改變。我國(guó)的抗震抗剪強(qiáng)度公式也以上面公式為基礎(chǔ)的，但是為設(shè)計(jì)方便

26、，不同的烈度區(qū)取用了相同的公式，均取為0.6，與上面提到的混凝土抗剪能力隨地震作用變化而不同的規(guī)律不一致，較為粗略。</p><p>　　延性對(duì)抗震來(lái)說(shuō)是極其重要的一個(gè)性質(zhì)，我們要想通過(guò)抗震措施來(lái)保證結(jié)構(gòu)的延性，那么就必須清楚影響延性的因素。對(duì)于梁柱等構(gòu)件，延性的影響因素最終可歸納為最根本的兩點(diǎn)：混凝土極限壓應(yīng)變，破壞時(shí)的受壓區(qū)高度。影響延性的其他因素實(shí)質(zhì)都是這兩個(gè)根本因素的延伸。如受拉鋼筋配筋率越大，混凝土受壓

27、區(qū)高度就越大，延性越差；受壓鋼筋越多，混凝土受壓區(qū)高度越小，延性越好；混凝土強(qiáng)度越高，受壓區(qū)高度越低，延性越好（但如果混凝土強(qiáng)度過(guò)高可能會(huì)減小混凝土極限壓應(yīng)變從而降低延性）；對(duì)柱子這類(lèi)偏壓構(gòu)件，軸壓力的存在會(huì)增大混凝土受壓區(qū)高度，減小延性；箍筋可以提高混凝土極限壓應(yīng)變，從而提高延性，但對(duì)于高強(qiáng)度混凝土，受壓時(shí)，其橫向變形系數(shù)較一般混凝土明顯偏小，箍筋的約束作用不能充分發(fā)揮，所以對(duì)于高強(qiáng)度混凝土，不適于用加箍筋的方法來(lái)改善其延性。此外，箍

28、筋還有約束縱向鋼筋，避免其發(fā)生局部壓屈失穩(wěn)，提高構(gòu)件抗剪能力的作用，因此箍筋對(duì)提高結(jié)構(gòu)抗震性能具有相當(dāng)重要的作用。根據(jù)以上規(guī)律，在抗震設(shè)計(jì)中為保證結(jié)構(gòu)的延性，常常采用以下措施：控制受拉鋼筋配筋率，保證一定數(shù)量受壓鋼筋，通過(guò)加箍筋保證縱筋不局部壓屈失穩(wěn)以及約束受壓混凝土，對(duì)柱子限制軸</p><p>　　按地震作用降低系數(shù)（“中震”的地面運(yùn)動(dòng)加速度與“小震”的地面運(yùn)動(dòng)加速度之比）來(lái)劃分延性等級(jí)，“小震” 取值越高，

29、延性要求越低，“小震”取值越低，延性要求越高。對(duì)延性要求則并未按關(guān)系來(lái)取對(duì)應(yīng)的，而是按抗震等級(jí)來(lái)劃分，抗震等級(jí)實(shí)質(zhì)又主要是由烈度分區(qū)來(lái)決定的。這就導(dǎo)致同一個(gè)R對(duì)應(yīng)了不同的，從而制定了不同的抗震措施，這與關(guān)系是不一致的。 另外，我國(guó)規(guī)定的“小震不壞，中震可修，大震不倒”的三水準(zhǔn)抗震設(shè)防目標(biāo)也存在一定的問(wèn)題。該設(shè)防目標(biāo)對(duì)甲類(lèi)、乙類(lèi)、丙類(lèi)這三類(lèi)重要性不同的建筑來(lái)說(shuō)，并不都是恰當(dāng)?shù)摹＿@種籠統(tǒng)的設(shè)防目標(biāo)也不符合當(dāng)今國(guó)際上的“多層次，多水準(zhǔn)性態(tài)控制

30、目標(biāo)”思想，這種多性態(tài)目標(biāo)思想提倡在建筑抗震設(shè)計(jì)中應(yīng)靈活采用多重性態(tài)目標(biāo)。甲類(lèi)建筑指重大建筑工程和地震時(shí)可能發(fā)生嚴(yán)重此生災(zāi)害的建筑，乙類(lèi)建筑指地震時(shí)使用不能中斷或需要盡快修復(fù)的建筑，由于不同類(lèi)別建筑的不同重要性，不宜再籠統(tǒng)的使用以上同一個(gè)性態(tài)目標(biāo)（設(shè)防目標(biāo)），此外，還應(yīng)該考慮建筑所有者的不同要求，選擇不同的設(shè)防目標(biāo)，從而做到在性態(tài)目標(biāo)的選擇上更加靈活。</p><p>　　4． 常用抗震分析方法</p>

31、;<p>　　伴隨著抗震理論的發(fā)展，各種抗震分析方法也不斷出現(xiàn)在研究和設(shè)計(jì)領(lǐng)域。</p><p>　　在結(jié)構(gòu)設(shè)計(jì)中，我們需要確定用來(lái)進(jìn)行內(nèi)力組合及截面設(shè)計(jì)的地震作用值。通常采用底部剪力法，振型分解反應(yīng)譜法，彈性時(shí)程分析方法來(lái)計(jì)算該地震作用值，這三種方法都是彈性分析方法。其中，底部剪力法最簡(jiǎn)便，適用于質(zhì)量、剛度沿高度分布較均勻的結(jié)構(gòu)。它的大致思路是通過(guò)估計(jì)結(jié)構(gòu)的第一振型周期來(lái)確定地震影響系數(shù)，再結(jié)合結(jié)

32、構(gòu)的重力荷載來(lái)確定總的水平地震作用，然后按一定方式分配至各層進(jìn)行結(jié)構(gòu)設(shè)計(jì)。對(duì)較復(fù)雜的結(jié)構(gòu)體系則宜采用振型分解反應(yīng)譜法進(jìn)行抗震計(jì)算，它的思路是根據(jù)振型疊加原理，將多自由度體系化為一系列單自由度體系的疊加，將各種振型對(duì)應(yīng)的地震作用、作用效應(yīng)以一定方式疊加起來(lái)得到結(jié)構(gòu)總的地震作用、作用效應(yīng)。而對(duì)于特別不規(guī)則和特別重要的結(jié)構(gòu)，常常需要進(jìn)行彈性時(shí)程分析，該方法為直接動(dòng)力分析方法。以上方法主要針對(duì)結(jié)構(gòu)在地震作用下的彈性階段，保證結(jié)構(gòu)具有一定的屈服水

33、準(zhǔn)。</p><p>　　對(duì)結(jié)構(gòu)抗震性能進(jìn)行分析是抗震研究的一項(xiàng)重要內(nèi)容，非線性時(shí)程分析，非線性靜力分析是目前常用的幾種抗震分析方法。其中針對(duì)結(jié)構(gòu)非線性反應(yīng)的非線性時(shí)程分析法（非線性動(dòng)力反應(yīng)分析），從建立在層模型或單列梁柱模型上的方法到建立在截面多彈簧模型上的方法，再到目前正在研究發(fā)展的建立在截面纖維滯回本構(gòu)規(guī)律的纖維模型法，模擬的準(zhǔn)確程度正在不斷提高。其基本思路是通過(guò)一系列數(shù)值方法建立和求解動(dòng)力方程從而得到結(jié)構(gòu)

34、各個(gè)時(shí)刻的反應(yīng)量。但由于對(duì)地震特點(diǎn)和結(jié)構(gòu)特性所做的假設(shè)，其結(jié)果存在不確定性，其主要價(jià)值是用來(lái)考察地震作用下普遍的而非特定的反應(yīng)規(guī)律，以及對(duì)抗震設(shè)計(jì)后的結(jié)構(gòu)進(jìn)行校核分析，評(píng)估其抗震性能。非線性靜力分析法是近年來(lái)得到廣泛應(yīng)用的一種結(jié)構(gòu)抗震能力評(píng)估的新方法。這種方法從本質(zhì)上說(shuō)是一種靜力非線性計(jì)算方法，但它將反應(yīng)譜引入了計(jì)算過(guò)程和結(jié)果。其根本特征是用靜力荷載描述地震作用，在地震作用下考慮結(jié)構(gòu)的彈塑性性質(zhì)。它的基本原理和步驟是先以某種方法得到結(jié)構(gòu)

35、在可能遭遇地震作用下所對(duì)應(yīng)的目標(biāo)位移，然后對(duì)結(jié)構(gòu)施加豎向荷載的同時(shí)，將表征地震作用的一組水平靜力荷載以單調(diào)遞增的形式作用到結(jié)構(gòu)上，在達(dá)到目標(biāo)位移時(shí)停止荷載遞增，最后在荷載</p><p><b>　　參考文獻(xiàn)</b></p><p>　　1．豐定國(guó)、王清敏、錢(qián)國(guó)芳、蘇三慶編，工程結(jié)構(gòu)抗震，地震出版社，20022．艾倫·威廉斯著，建筑與橋梁抗震設(shè)計(jì)，中國(guó)水利

36、水電出版社，20023．王社良、曹照平，框架結(jié)構(gòu)彈塑性性能試驗(yàn)研究，工程力學(xué)，1998：15（2）4．周錫元等，建筑結(jié)構(gòu)的隔震、減震和振動(dòng)控制，建筑結(jié)構(gòu)學(xué)報(bào)，2002：25．周云、徐彤，耗能減震技術(shù)的回顧與展望，力學(xué)與實(shí)踐，2000：20</p><p><b>　　附錄二：</b></p><p>　　Earthquake resistance design

37、development</p><p>　　Abstract: 1, earthquake resistance design mentality development course; 2, modern earthquake resistance design mentality; 3, guarantee structure ductility ability earthquake resistance m

38、easure; 4, commonly used earthquake resistance analysis method</p><p>　　Key word: Structural design earthquake resistance</p><p>　　1. Earthquake resistance design mentality development course<

39、;/p><p>　　Along with the construction structure earthquake resistance correlation fundamental research unceasing development, the structure earthquake resistance design mentality has also experienced a series o

40、f changes. At first, in has not considered the structure elastic dynamic characteristic, also does not have the detailed earthquake function recording statistical data under the condition, the experience takes an earthqu

41、ake level function (0.1 time of dead weight) to use in the structural design. Is</p><p>　　2. Modern earthquake resistance design mentality</p><p>　　Modern earthquake resistance design mentality

42、 forms which under the current earthquake resistance theory, its main content is:</p><p>　　(1) The reasonable choice determination structure submits the standard earthquake function. First by has the statist

43、ical significance the ground peak value acceleration to take generally this local earthquake strong and the weak symbolized the value (namely center shakes), then (seismic force step-down ratio) obtains the different des

44、ign by different R (namely slightly to shake) with the ground movement acceleration carries on the structure the intensity design, thus had determined the structure</p><p>　　(2) Which formulates the effectiv

45、e earthquake resistance measure to cause the ductility ability which the structure truly has when design to use R corresponds. Mainly includes the endogenic force adjustment measure (strong column weak beam, strong cuts

46、weak is curved) and the earthquake resistance structure measure.</p><p>　　The modern earthquake resistance design idea is based on establishes to the structure inelastic performance research in, its core is

47、the relations, the relations mainly refers differently is stagnating under the rule and the ground movement characteristic, the structure submits the standard and the self oscillation cycle as well as the biggest inelast

48、ic dynamic response relations. R is the ball plasticity responds the seismic force step-down ratio, the abbreviation seismic force step-down ratio;</p><p>　　The reason that has the appeal the rule, we should

49、 note to reinforced concrete structure some related characteristics. First, may enable the structure through the artificial measure to have the certain ductility, namely the structure under exterior function, may have th

50、e enough non-linear distortion, but also maintains the supporting capacity the attribute. Like this may guarantee the structure when enters the big non-linear distortion, cannot appear because the intensity to drop the s

51、erious des</p><p>　　Along with to rule understanding thorough, this rule has been accepted by the various countries' standard. When earthquake resistance design, to in the identical intensity area identi

52、cal kind of structure, may use different R according to the situation, also is different uses in the intensity design earthquake function. When R value big, namely uses in the earthquake function which designs comparing

53、the hour, is stricter to the structure ductility request; Otherwise, when R value small, when nam</p><p>　　Should use the multiple condition goal to the construction earthquake resistance design, To the gene

54、ral structure, the essential structure, to were safe the control action the structure to suggest separately the corresponding condition goal - basic goal (often met under earthquake completely normally to operate, little

55、 met under earthquake normal operation, met under earthquake to guarantee rarely safety, met under earthquake close to collapse extremely rarely), the essential goal (is short unde</p><p>　　3.Guarantees the

56、structure ductility ability the earthquake resistance measure</p><p>　　After reasonably chose the structure to submit the standard and the ductility request, needed through the earthquake resistance measure

57、to guarantee the structure had the ductility ability truly which needed, thus the guarantee structure shook, under the big quake in the center realizes the earthquake resistance to garrison the goal. System earthquake re

58、sistance measure including following several aspects content:</p><p>　　(1) "Strong column weak beam": Artificial increases the column to be opposite in beam's anti- curved ability, causes the r

59、einforced concrete frame under the big quake, the beam end plastic hinge appears early, in achieved when biggest non-linear displacement the plastic rotation is big; But the column end plastic hinge appears late, in achi

60、eved when biggest non-linear displacement the plastic rotation is small, even simply does not appear the plastic hinge. Thus the guarantee frame has a stabler</p><p>　　(2) "Strong cuts weakly is curved&

61、quot;: The shearing failure basically does not have the ductility, once some spot has the shearing failure, this spot on thoroughly will withdraw from the structure earthquake resistance ability, also possibly will cause

62、 the structure regarding the column end shearing failure the part or the whole collapses. Therefore may artificial increase the column end, beam section, the pitch point combination shearing force value, enables the stru

63、cture the inelasticity to disto</p><p>　　(3) Earthquake resistance structure measure: Through the earthquake resistance structure measure guaranteed forms the plastic hinge the spot to have the enough plasti

64、c deformation ability and the plasticity consumes energy the ability, at the same time guarantees the structure the integrity.</p><p>　　This system earthquake resistance measure idea has been accepted by the

65、 various countries, but regarding consumed energy the organization to appear actually take New Zealand and US as representative's two kind of quite same not less than mentalities. First, these two kind of mentalities

66、 all are take first guide the beam end to leave the plastic hinge as the premises.</p><p>　　Resists earthquakes the researcher to think consumes energy the organization suitably to use conforms to in the mec

67、hanics of plasticity "the ideal beam articulation organization", namely the beam end forms the plastic hinge completely, at the same time the first floor base of cylinder also all forms the plastic hinge "

68、the entire structure plastic organization". Its concrete procedure is obtains various components combination endogenic force value after the structure analysis, presses the combina</p><p>　　Others thoug

69、ht takes column bending moment enhancement coefficient oversized, according to experienced has taken the small column bending moment enhancement coefficient, this procedure caused the structure in the inelastic distortio

70、n process which the big quake caused, the beam end plastic hinge formed early, the column end plastic hinge formed relatively late, the beam end plastic hinge formed is common, the column end plastic hinge formed relativ

71、ely few somewhat, thus formed "the beam column p</p><p>　　"The ideal beam articulation organization" the earthquake resistance measure advantage lay in "the ideal beam articulation organi

72、zation" to use the ductility and the plasticity completely consumes energy the ability good beam end plastic hinge to realize the frame ductility and the diffusion earthquake energy, at the same time because did not

73、 appear the plastic hinge besides the first floor base of cylinder other column ends, also did not need again to these column end Canada more stirrups. But </p><p>　　Therefore does not need to limit by the m

74、echanics of plasticity organization concept below, so long as can realize the plasticity under the big quake to consume energy the organization, can guarantee the earthquake resistance design the basic request:</p>

75、<p>　　(1) Consumes energy by the beam end plastic hinge primarily.</p><p>　　(2) Does not limit the column end plastic hinge to appear (including first floor base of cylinder), but enable it through th

76、e suitable enhancement column end anti- curved ability method to have the enough allowance under the big quake plastic rotation to its plastic rotation ability.</p><p>　　(3) The end at the same time is not a

77、t the plastic deformation condition with the level various columns about.</p><p>　　In our country's earthquake resistance measure to consumed energy the organization consideration also basically to follo

78、w this mentality, has used "the beam column plastic hinge organization" the pattern.</p><p>　　In earthquake resistance design we in order to avoid not having the ductility shearing failure the occu

79、rrence, took "strong cut weakly is curved" the measure to process the component to bend the ability with to cut the ability the relational question. The worth noting is, with must resists earthquakes anti- cuts

80、 the destruction to compare, under the earthquake function shearing failure is different. Take the beam component as the example, under the big earthquake function, the beam end forms alt</p><p>　　When the e

81、arthquake function more and more hour, the beam end possibly does not appear the double syncline crack, but appears the single syncline crack, the crack opening growth also from is bigger than the non- earthquake resista

82、nce situation to approach the non- earthquake resistance situation, anti- cuts the environment to be more and more advantageous. In addition, resists earthquakes anti- cuts the request structural unit to be supposed unde

83、r the big quake to estimate achieved in front of i</p><p>　　In summary, with must resists earthquakes anti- cuts compares, resists earthquakes anti- cuts the performance is different, its performance and the

84、 shearing force function environment, the plastic area ductility request size concerns. Below we may adopt the formula to consider resists earthquakes anti- cuts the intensity formula.</p><p>　　Anti- cuts th

85、e ability for the concrete, anti- cuts the ability for the stirrup, for because the earthquake function causes the concrete anti- cuts the reduction coefficient which the ability drops, also along with the shearing force

86、 function environment, the ductility request but changes. Our country's earthquake resistance shearing strength formula also take above formula as foundation, but for the design convenient, the different intensity ar

87、ea has used the same formula, takes is 0.6, mention</p><p>　　The ductility to resists earthquakes said is an extremely important nature, we must want to guarantee the structure through the earthquake resista

88、nce measure the ductility, then must clearly affect the ductility factor. Regarding component and so on beam column, the ductility influence factor finally may induce into the most basic two points: Concrete limit pressu

89、re strain, time destruction compression zone altitude. The influence ductility other factors essence all is these two basic factors ex</p><p>　　("Center shakes" ground movement acceleration accordi

90、ng to the earthquake function step-down ratio with "slightly shakes" ratio of the ground movement acceleration) to divide the ductility rank, "slightly shakes" the value high, ductility request lower,

91、 "slightly shakes" the value lowly, the ductility request is higher. To ductility request then presses by no means relates takes the correspondence, but is divides according to the earthquake resistance rank, t

92、he earthquake resistance rank essence</p><p>　　4. Commonly used earthquake resistance analysis method</p><p>　　Is following the earthquake resistance theory development, each earthquake resistan

93、ce analysis method also unceasingly appears in the research and the design domain. In the structural design, we need to determine uses for to carry on the endogenic force combination and the section design earthquake vir

94、tual value. Usually uses the base shearing force law, inspires the decomposition reaction spectral method, the elastic time interval analysis method calculates this earthquake virtual value, these </p><p>　　

95、Carries on the analysis to the structure earthquake resistance performance is resists earthquakes the research an important content, the non-linear time interval analysis, the non-linear static analysis is the present co

96、mmonly used several earthquake resistance analysis method.In which in view of the structure non-linearity response non-linear time interval analytic method (non-linear dynamic response analysis), from the establishment i

97、n the level model or on the single row beam column model met</p><p><b>　　Reference</b></p><p>　　1.Fengdingguo, Wangqingmin, Qianguofang, Susanqing, Engineering structure earthquake r

98、esistance, Earthquake Publishing house,2002</p><p>　　2.Aylen?Williams, Construction and bridge earthquake resistance design, Chinese Water conservation Water and electricity Publishing house,2002</p>