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1、建筑结构设计中的安全度和可靠度探讨广州智海建筑设计有限公司朱 翔来源：建筑学研究前沿2012年第12期摘要：安全度是衡量结构设计安全程度的“尺度”，安全度设计经历了极限状态设计法、容许应力设计法、破损阶段设计法等到概率极限状态设计法的重大变化。概率极限状态设计明确了可靠度的概念。由于目前对安全度和可靠度的认识仍存疑议，笔者不惮肤浅，对其中一些观点进行了探讨。关键词：安全度 可靠度 结构设计建筑结构的安全度，通俗地讲就是度量结构安全程度的尺度。安全度在结构中首先是一个设计概念，通过赋予一定的“安全量”，达到在预定使用期限内满足适用性、安全性和耐久性的要求。安全度的设计经历了极限状态设计法、容许应
2、力设计法、破损阶段设计法等直到概率极限状态设计法的重大变化。概率极限状态设计法明确了可靠度概念，即结构在规定时间和条件下，完成前述预定功能的概率。目前，对安全度仍然存在着一些争议，实际上每逢重大事故发生时都会存在着一些质疑，这也反映了人们希望建筑结构安全可靠的良好愿望。笔者不惮肤浅，也对安全度、可靠度的相关问题进行一些探讨，希望通过切磋辨明事理，有助于设计中合理把握安全度。1 安全度和可靠度争议的焦点1.1 安全度的观点十几年前，安全度就是结构设计中论争的焦点之一，主要围绕规范标准中的安全度指标是偏低还是适中的，现在结构设计中的主要规范都已修订再版过至少一次以上，但争议并没有停息。下面介绍争论
3、的论点和论据。1.1.1 安全度偏低，需要大幅提高安全度比较系统地提出结构规范中安全度偏低观点的是陈肇元教授，他的理由1是：构造配筋量偏低。如GBJ10-89混凝土结构设计规范中规定柱子受压钢筋最小配筋率为0.4%，比前苏联1949年规范的0.5%还要低。比较一下GB 50010-2010混凝土结构设计规范受压构件纵向钢筋最小配筋率：强度500MPa为0.5%；400MPa为0.55%；300、335MPa为0.6%。载荷设计标准值偏低。如GBJ 9-87建筑结构荷载规范以恒载标准值G和活载标准值Q组合后的计算值是，美国是，英国，我国荷载设计值比英美低80%。GB 50009-1012建筑结构
4、荷载规范已有所提高，永久荷载分项系数取1.2，永久荷载控制组合时取1.35；可变载荷分项系数取1.4，标准值大于4工业厂房楼面活载取1.3。材料强度设计值比英美高。混凝土至少高出5%10%，钢筋至少高3%6%。但国外材料检测更严，我国材料实际保证率是偏低的。我国规范中的材料分项系数比英美低，混凝土：中国1.35，英国1.50，美国1.41（受压）；钢筋：中国1.08，英国1.35，美国1.41（受压）。所以，我国结构安全度也偏低。GB 50010-2010的混凝土强度设计值已略调低（C50以下）。构件承载力计算公式不精确，使安全度偏低。如GBJ10-89正截面强度计算采用，使附近构件偏于不安全
5、。斜截面抗剪强度也存在众所周知的错误。GB 50010-2010已做了修正。支持上述观点的文献不少，如安颖工程师2则以宁波跨海大桥断裂事故和宝钢建设中与日方专家就安全度争执的例子作为论据，说明需要大幅提高安全度。1.1.2 安全度合适，不需要大幅提高安全度这方面论点和论据主要如下3：安全事故与结构安全度无关。举了上世纪50年代结构设计为例，那时混凝土标号只有110140号，施工技术也比较落后，但安全事故很少。北京王府井百货大楼、北京饭店等都经历了唐山地震的考验。GB 50011-2010建筑抗震设计规范中说明严格按照GB 50011-2001规范进行设计、施工和使用的建筑，遭遇汶川大地震且超过
6、设防烈度一度的情况下，达到了抗震设防目标。规范中安全度并非都比国外低。规范规定柱子最小钢配筋率0.4%，是不考虑抗震要求，如考虑抗震，高层建筑最小钢筋配筋是0.5%1.0%，而且实际设计时还会更大，因此与国外相比用钢量并不会少。现有规范不会成为进入国际市场的障碍。在北京一些按现有规范建造的大型办公楼为外国跨国公司购买。外商认为中国建筑的问题是施工质量低劣和构件设计浪费，用钢太多和混凝土构件截面太大。结构设计应提倡节约，目前仍应节约钢材。规范要按照国家政策而定。规范不仅是技术性的，还反映经济条件，因此作为发展中国家比发达国家安全度低是正常的。而且过去几十年的考验，说明安全度基本满足要求。1.2
7、可靠度的观点目前反对用可靠度衡量安全度的观点比十几年大为减少，但认为可靠度仍有“瑕疵”：认为概率可靠度理论需要大量数据统计做基础，但荷载和抗力统计方面还存在问题；结构可靠度分析的三个基础点还不完善；可靠度理论强调正常设计、施工、使用的“三个正常”，但正常和不正常界限未明确；认为分项安全系数方法更灵活实用等4。2 安全度和可靠度拙见2.1 关于安全度的见解笔者同意陈肇元教授关于我国规范中安全度比英美等国标准低的观点，因为这是事实，而事实是不容否认的，但不提倡大幅度提高规范安全度，理由如下：我国的规范体系与国外是不同的，在司法中的效用也是不一样的。不错，我国结构规范是强制性的，而英美等国是推荐性的
8、。但这与法律体系的差异有很大关系。我国法律讲究“以事实为依据，法律为准绳”，结构规范中的条文、数据会成为我国法律判决的依据；而英美等国实行陪审团制度，审判时规范虽然也会被参考，但不是唯一的，即使符合规范也会判有罪，没有遵守规范也可能判无罪。所以，我国结构规范给出的数据是保证最低限度安全的，安全度低一些是很正常的。有些设计人员对我国结构规范的理解有偏差，认为规范规定的数据就是用来设计的数据。实际上规范规定的一些数据是最低限度的，实际设计时完全可以根据设计需要进行调整。而对于一些“设计浪费”的现象，笔者认为这是设计人员心中无底又怕担责的表现。目前我国结构设计师的培养和资格认定与解放初期到文革前这段
9、时间有很大差别，那时比较注重实际能力的培养，学业完成可以很快适应设计工作；而现在由于知识爆炸，所要传授的理论知识多，必然影响到实际操作能力，现在很多毕业生不会设计，结构设计师的考试也主要是考察理论和规范，实际设计能力无法通过很短时间的考试就完全得到检验。优秀的设计师也肯定不是通过考试就能考出来的。建议行业协会制定一些推荐性的标准，设定作为偏于安全的“上限”。但笔者还是认为有效提高设计水平是关键，这既有个人因素，国家社会也有责任。2.2 有关可靠度的意见笔者认为可靠度其实就是用来衡量并保证安全度的“尺度”，以极限状态下的概率取代偏于经验的安全系数是一种进步的表现，这一点毋庸置疑。从主要凭经验走向
10、理性和量化是科技和社会发展的必然趋势。至于“瑕疵”，是需要今后继续完善的。实际上任何事物都不存在“完美”一说，有“瑕疵”也是正常的。3 结语由于结构设计安全度事关人民的生命财产安全，对其进行争鸣辩论有助于辨明事理，更好地应用和改善安全度。目前的结构规范虽然不完善，但会继续改进。正确理解和应用规范是每一名设计人员从事设计工作的基础，应遵守和用好规范。参考文献：1 陈肇元. 要大幅度提高建筑结构设计的安全度J. 建筑结构，1999(1).2 安颖. 大幅度提高建筑结构设计安全度的必要性J. 安徽冶金科技职业学院学报，2010,20(4).3 李广辉. 关于提高建筑结构设计安全度的建议J. 中华民居
11、，2010(11).4 熊健. 阐述建筑结构设计中的安全度问题J. 江西建材，2011(2).第 53 页 共 53 页（英文版 ） Two regulations promulgated for implementation is in the party in power for a long time and the rule of law conditions, the implementation of comprehensive strictly strategic plan, implementation in accordance with the rules and disc
12、ipline to manage the party, strengthen inner-party supervision of major initiatives. The two regulations supporting each other, the adhere to a positive advocate, focusing on morality is of Party members and Party leading cadres can see, enough to get a high standard; around the party discipline, di
13、sciplinary ruler requirements, listed as negative list, focusing on vertical gauge, draw the party organizations and Party members do not touch the bottom line . Here, the main from four square face two party rules of interpretation: the first part introduces two party Revised regulations the necess
14、ity and the revision process; the second part is the interpretation of the two fundamental principles of the revision of laws and regulations in the party; the third part introduces two party regulations modified the main changes and needs to grasp several key problems; the fourth part on how to gra
15、sp the implementation of the two regulations of the party. and revised the necessity and revised history of the CPC Central Committee the amendment to the Chinese Communist Party members and leading cadres honest politics several guidelines and column 1 by 2015 to strengthen party laws and regulatio
16、ns focus. Two party regulations revision work lasted a Years, pooling the wisdom of the whole party, ideological consensus, draw historical experience, respect for the wisdom of our predecessors, which reflects the unity of inheritance and innovation; follow the correct direction, grasp the limited
17、goals, adhere to the partys leadership, to solve the masses of the people reflect a focus on the problem. The new revision of the and , reflects the partys 18 and the eighth session of the third, the spirit of the fourth plenary session, reflecting the experience of studying and implementing the Gen
18、eral Secretary Xi Jinping series of important speech, reflects the partys eighteen years comprehensive strictly practice. (a) revised two regulations of the party need of in based on revised, the promulgation and implementation of January 2010, to strengthen the construction of the contingent of lea
19、ding cadres play an important role. But with the party to manage the party strictly administering the deepening, has not been able to fully meet the actual needs. Content is too complicated, eight prohibition, 52 are not allowed to hard to remember, and also difficult to put into practice; the secon
20、d is concisely positive advocated by the lack of prohibited provisions excessive, no autonomy requirements; the third is banned terms and discipline law, both with the party discipline, disciplinary regulations repeat and Criminal law and other laws and regulations repeat; the fourth is to clean the
21、 theme is not prominent, not for the existing problems, and is narrow, only needle of county-level leading cadres above. is in 1997 based on revision, in December 2003 the promulgation and implementation, to strengthen the construction of the party play very important role. Along with the developmen
22、t of the situation, which many provisions have been unable to fully meet the comprehensive strictly administering the practice needs. One is Ji law, more than half of the provisions and criminal law and other countries laws and regulations Repetition; two is the political discipline regulations is n
23、ot prominent, not specific, for violation of the party constitution, damage the authority of Party Constitution of misconduct lack necessary and serious responsibility to pursue; third is the main discipline for the leading cadres, does not cover all Party members. Based on the above situation, need
24、 to and the two is likely to be more relevant regulations first amendment. By revising, really put the authority of Party discipline, the seriousness in the party tree and call up the majority of Party members and cadres of the party constitution of party compasses party consciousness. (II) two part
25、y regulations revision process the Central Committee of the Communist Party of China attaches great importance to two regulations revision . Xi Jinping, general books recorded in the Fifth Plenary Session of the eighth session of the Central Commission for Discipline Inspection, on the revised regul
26、ations made clear instructions. According to the central deployment, the Central Commission for Discipline Inspection from 2014 under six months begin study two regulations revision. The Standing Committee of the Central Commission for Discipline Inspection 4 review revised. Comrade Wang Qishan 14 t
27、imes held a special meeting to study two regulations revision, amendment clarifies the direction, major issues of principle, path and target, respectively held a forum will listen to part of the province (area) secretary of the Party committee, Secretary of the Discipline Inspection Commission, part
28、 of the central ministries and state organs Department The first party committee is mainly responsible for people, views of experts and scholars and grassroots party organizations and Party members. Approved by the Central Committee of the Communist Party of China, on 7 September 2015, the general o
29、ffice of the Central Committee of the Party issued a notice to solicit the provinces (autonomous regions, municipalities) Party, the central ministries and commissions, state ministries and commissions of the Party (party), the General Political Department of the military, every 3 people organizatio
30、n of Party of two regulations revision opinion. Central Commission for Discipline Inspection of extensive solicitation of opinions, careful study, attracting, formed a revised sent reviewers. In October 8 and October 12, Central Committee Political Bureau Standing Committee and the Political Bureau
31、of the Central Committee After consideration of the two regulations revised draft. On October 18, the Central Committee of the Communist Party of China formally issued two regulations. Can say, two laws amendment concentrated the wisdom of the whole party, embodies the party. Second, and revision of
32、 the basic principles of two party regulations revision work and implement the partys eighteen, ten eight plenary, the spirit of the Fourth Plenary Session of the Eleventh Central Committee and General Secretary Xi Jinping important instructions on the revised and , highlighting the ruling party cha
33、racteristics, serious discipline, the discipline quite in front of the law, based on the current, a long-term, advance as a whole, with Bu Xiuding independent and . Main principle is: first, adhere to the party constitution to follow. The constitution about discipline and self-discipline required sp
34、ecific, awaken the party constitution of party compasses party consciousness, maintaining the authority of the constitution. General Secretary Xi Jinping pointed out that no rules, no side round. Party constitution is the fundamental law, the party must follow the general rules. In early 2015 held t
35、he eighth session of the Central Commission for Discipline Inspection Fifth Plenary Session of the 16th Central Committee, Xi Jinping again pointed out that constitution is the party must follow the general rules, but also the general rules. the revision of the and is Method in adhere to the regulat
36、ions established for the purpose of combining rule of virtue is to adhere to the party constitution as a fundamental to follow, the constitution authority set up, wake up the party constitution and party rules the sense of discipline, the party constitution about discipline and self-discipline speci
37、fic requirements. 4 second is to adhere to in accordance with the regulations governing the party and the party. The Party of rule of virtue de, mainly refers to the partys ideals and beliefs, excellent traditional style. The revised the closely linked to the self-discipline, insisting on the positi
38、ve initiative, for all members, highlight the vital few, emphasized self-discipline, focusing on the morality, and the majority of Party members and the ideological and moral standards. The revised Ji method separately, Ji, Ji Yan to Method, as a negative list, emphasizing the heteronomy, focusing o
39、n vertical gauge. Is this one high and one low, a positive reaction, the strict party discipline and practice results transformation for the integration of the whole party to observe moral and discipline requirements, for the majority of Party members and cadres provides benchmarking and ruler. Thir
40、d, insist on to. In view of the problems existing in the party at the present stage, the main problems of Party members and cadres in the aspect of self-discipline and abide by the discipline to make clearly defined, especially the partys eighteen years strict political discipline and political rule
41、s, organization and discipline and to implement the central eight provisions of the spirit against the four winds and other requirements into Disciplinary provisions. Not one pace reachs the designated position, focusing on in line with reality, pragmatic and effective. After the revision of major c
42、hanges, major changes in the and modified and needs to grasp several key problems (a) adhere to according to regulations governing the party and party with morals in combination, for at the present stage, the leadership of the party members and cadres and Party members in existing main problems of s
43、elf-discipline, put forward principles, requirements and specifications, showing Communists noble moral pursuit, reflected at all times and in all over the world ethics from high from low 5 common requirements. One is closely linked to the self-discipline, removal and no direct relation to the provi
44、sions of . the second is adhere to a positive advocate, eight prohibition 52 are not allowed to about the content of the negative list moved into synchronization amendment . Three is for all the party members, will apply object from the leadership of the party members and cadres to expand to all Par
45、ty members, fully embodies the comprehensive strictly required. The fourth is prominent key minority, seize the leadership of the party members and cadres is the key, and put forward higher requirements than the ordinary Party members. Five is to simplify, and strive to achieve concise, easy to unde
46、rstand, easy to remember. The revised is the ruling Party since the first insists on a positive advocate forAll Party members and the self-discipline norms, moral declaration issued to all members of the party and the National Peoples solemn commitment. criterion of a clean and honest administration
47、 consists of 4 parts, 18, more than 3600 words. After the revision of the , a total of eight, 281 words, including lead, specification and Party member cadre clean fingered self-discipline norms, etc. Part 3 members low-cost clean and self-discipline, the main contents can be summarized as four must eight code. Lead part, reiterated on ideal and faith, fundamental purpose, the fine traditions and work style, noble sentiments,