框架结构自振周期折减系数

框架结构自振周期折减系数 由于计算模型的简化和非结构因素的作用，导致多层钢筋混凝土框架结构在弹性阶段的计算自振周期(下简称“计算周期”)比真实自振周期(下简称“自振周期”)偏长。因此，无论是采用理论公式计算还是经验公式计算;无论是简化手算还是采用计算机程序计算，结构的计算周期值都应根据具体情况采用自振周期折减系数(下简称“折减系数”)加以修正，经修正后的计算周期即为 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 采用的实际周期(下简称“设计周期”)，设计周期=计算周期×折减系数。如果折减系数取值不恰当，往往使结构设计不合理，或造成浪费、或甚至产生安全隐患。诚然，折减系数是钢筋混凝土框架结设计所需要解决的一个重要问题。 影响自振周期因素是诸多方面的，加之多层钢筋混凝土框架结构实际工程的复杂性，抗震 规范 编程规范下载gsp规范下载钢格栅规范下载警徽规范下载建设厅规范下载 [1]没有、也不可能对折减系数给出一个确切的数值。许多文献中给出，当主要考虑填充墙的刚度影响时，折减系数可取0.6~0.7[4] [7];根据填充墙的多少、填充墙开洞情况，其对结构自振周期影响的不同，可取0.50~0.90[2].这些都是以粘土实心砖为填充墙的经验值，不言而喻，采用不同填充墙体材料的折减系数是不相同的。当采用轻质材料或空心砖作填充墙，当然不应该套用实心砖为填充墙的折减系数。对于粘土实心砖外的其它墙体可根据具体情况确定折减系数[4]. 通过笔者的粗浅 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 和工程实践摸索，指出影响自振周期的一些主要因素，并对折减系数的取值提出建议，供结构工程师参考。 计算周期与自振周期存在差异的诸多因素 international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 结构计算分析总是要进行简化的，简化程度取决于当时的计算工具;简化是有条件的，而关键是简化模型尽可能符合真实受力模型。多层钢筋混凝土框架结构的计算周期往往与其自振周期有较大出入，笔者认为，此偏差主要来自计算模型的简化，没有计入那些难于准确计算的因素造成的。一分为二的说，没有计入的那些因素，常常使计算周期比自振周期长，在一定条件下也会使计算周期比自振周期短，主要表现为以下几方面: (一)造成计算周期比自振周期长的诸多原因 1. 填充墙的刚度影响 大多数多层钢筋混凝土框架结构的设计计算中，并没有计算填充墙、装修(饰)材料、支撑、设备等非结构构件的刚度。实际工程中，由于未考虑砖填充墙的刚度常常使计算周期比实测自振周期(下简称“实测周期”)大很多[7].填充墙的影响与填充墙的材料性能、数量、单片墙体长度、墙体完整性(开洞情况)、与框架的连接情况息息相关。定性地说，填充墙的数量多、单片墙体长度大、墙体开洞少且小、与框架连接好，它对框架结构的刚度增加大，反之就小。 我国的框架填充墙的发展趋势是，逐步取消粘土砖(保护粘土资源、能源、环境等的要求)，采用多样化轻质填充砌体、轻墙板取而代之。采用不同材料的填充墙，由于填充墙材料的刚度、变形性能、延性的不同，其对结构的空间刚度影响显然不相同。在其它条件相同时，采用轻质填充墙比粘土砖填充墙对结构的刚度影响小。 一般框架结构都要有填充墙，当砖填充墙多，可能会成为影响结构international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 自振周期的主要的直接因素。 2. 基坑回填土及混凝土刚性地坪对底层框架柱的侧限作用 通常，在计算模型中，多层钢筋混凝土框架结构的底层柱高(计算高度)，一般取基顶至一层楼盖顶之间的距离，见下图1.由于基顶至室内、外之间回填土必须严格夯实。例如压实填土地基要求回填土的压实系数不应小于0.94[3].而且，通常在室内都要作混凝土刚性地坪。填土及地坪对结构侧移的约束，完全可以改变底层柱的计算高度，增大了结构刚度。为考虑填土及地坪影响，加强了底层柱根及其在刚性地坪部位的构造措施[1]. 当基础埋深大，填土密实，混凝土地坪刚度大时，也是造成计算周期比实测周期偏长的重要原因。 3. 现浇楼板对楼面梁的刚度影响 目前，常规的多层钢筋混凝土框架结构的分析计算，通常采用杆元结构模型，如PK采用平面杆元模型，TAT、TBSA等采用空间杆元模型。但是，客观上，现浇楼板形成了结构的刚度。在结构设计时参考了教科书及许多文献，采用简化方法考虑了现浇楼板对楼面梁的刚度增大系数。比如，边框架梁取1.5倍，中框架梁取2.0倍[4].但是，这并不足以反应现浇楼板作为梁的有效翼缘对线形杆元模型梁的惯性矩真实增大了多少，在弹性阶段，此增大系数完全可能大于2.0[5].准确计算是无法做到的，也只能经验考虑。若增大系数值取小了，计算所得的结构刚度偏小，即计算周期偏长。现浇楼板对楼面梁的刚度增大系数取值，也直接影响着结构的计算周期。 international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 4. 计算荷载高估了结构真实质量 一般情况下，计算荷载不同程度地高估了结构的真实质量(或简化的振动质点质量)。对于恒荷载构成的质量，在正常设计情况下，计算值必然大于实际值;对于活荷载构成的简化质点质量，比如楼面等效均布荷载按50%考虑[1]，出现这样满载布置情况也是不太可能的。因此，所得简化质点质量之和往往大于真实结构质量，数值计算所得的周期自然偏大。 5.结构构件的超强性 首先，对材料强度具有95%保证率的可靠度要求[8]，材料(如混凝土、钢筋等)存在超强因素;其次，设计和施工都要求结构构件的实际强度(如指标E)、尺寸(如指标I)不得低于设计 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 。再者，混凝土的强度和其他性能指标的标准，一般取龄期t=28天来标定，而一般情况下混凝土的抗压强度是随龄期单调增长的，其增长速度渐减并趋向收敛。如，规范CEB-FIP MC 90中，混凝土的抗压强度及弹性模量随龄期增长的计算式分别为:fC(t)= fC ;EC(t)= EC 式中 =e .当然，正常情况下，结构的实际刚度也就大于设计计算刚度。 (二)自振周期是变化的——特别是结构进入弹塑性、塑性变形阶段也会出现计算周期比 自振周期短的情形 混凝土构件的刚度是随变形和应力状态、配筋情况、时间等诸多因素变化的。自然，其自振周期也随之而改变。 1. 结构刚度随不同变形阶段而变化 无论是结构构件还是非结构构件，随着结构变形不断增加、自身开international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 裂直至破坏的过程中，其刚度逐渐衰减，同时阻尼在增加，才致使地震作用内力不会直线上升。当结构的侧向变形达到一定范围后，填充墙出现开裂、破坏，现浇楼板、刚性地坪等的刚度也退化和逐渐破坏。同时，随着结构构件开裂，按弹性计算的周期应该作相应调整，以反应非结构构件抗侧移刚度降低甚至消失和结构构件刚度的折减。当计算变形较大时，结构构件按弹性计算的刚度宜折减，如取0.85EcI0[1]. 2. 实测自振周期随外界的干扰力大小而变化 钢筋混凝土结构的自振周期，在大振幅振动与微幅振动下是不同的。对同一结构来说，地震作用由小至大，自振周期也由短变长。例如，北京饭店东楼横向基本实测周期，在地震前(脉动法实测值)、海城地震时、唐山地震时分别测得0.90秒、0.95秒、1.40秒。而且，结构并未进入明显的塑性变形，震后仅有填充墙轻微开裂[7].也就是说，结构构件进入塑性变形之前，建筑物的抗侧移刚度已经明显降低，自振周期比微幅振动时(脉动法实测值)已经增加了许多。 3. 钢筋混凝土构件带裂缝工作性质 大多钢筋混凝土构件是带裂缝工作的。钢筋混凝土受弯构件的刚度，随时间、长驻荷载、配筋率而变化，短期刚度可按下式计算[6]: 其中 ;长期刚度可按下式计算: ，其中长期荷载作用下对挠度增大的影响系数θ与纵向受压钢筋配筋率等因素有关，一般长期刚度小于短期刚度。 钢筋混凝土受弯构件，当弯矩M大于开裂弯矩Mr后，随着弯矩M(或弯曲应力)增大，构件上裂缝开展深度增加，截面有效高度减小international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 而刚度降低。但是，在弹性变形阶段，裂缝对受弯构件的刚度影响较小，当进入弹塑性和塑性变形阶段，裂缝对受弯构件的刚度影响是不可忽略的因素。 (三)其它影响因素的说明 1.空间布置的差别 建筑的空间整体工作性能、平面布置、实际质量(包括荷载)分布、场地地基和基础、施工质量、材料性能等等，都会对结构的自振周期产生影响。 2.算简图忽略诸多次要因素产生的模型化误差 计算模型的假定和边界条件的处理，比如，实际结构的质量沿竖向是连续分布的，振动质点的简化与实际建筑存在连续介质离散化的物理意义上的模型化差异。自然也就存在计算结果的数值差异。 总而言之，由于钢筋混凝土材料性能的离散性、变形成分的多样和影响因素的众多。很难建立一个通用的可用于精确计算的本构模型。对任意框架结构和同一框架结构的弹性、弹塑性、塑性变形的各阶段给定同一周期折减系数计算显然是不恰当的，也是不切合实际的。从上述各种因素的分析和根据大量实测统计(计算周期平均为实测自振周期的2.5~3倍[7])，在弹性计算阶段，计算周期比自振周期偏长。 采用折减系数要求结构刚度、质量(荷载)、填充墙在平面内和沿竖向均匀分布 多层框架结构，由于框架柱布置灵活，随着建筑功能的复杂性、多样性增强，大空间结构、复杂结构、特殊结构的日益增多，抗震的概international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 念设计、构造设计更显得重要，对关键部位、薄弱环节的加强必须具有针对性、有效性。对这类结构，靠自振周期折减以增大地震作用效应来增加结构安全性，并不一定奏效，还可能会使结构构件受力失真。例如: 1. 填充墙在平面内均匀分布的要求 准确的说，由于填充墙的刚度影响，必须考虑填充墙的位置及分布。比如下图2，仅当1，2轴之间有砖填充墙。图中框架柱,,的抗弯刚度(EI)为,,的8倍多，相应的其抗侧移刚度也比,,超出许多倍。就,,，,,而言，如果考虑填充墙的刚度影响，采用周期折减系数予以调整，水平地震作用产生的内力增加部分，按抗侧移刚度分配，绝大部分由,,承担，并未针对性的考虑与填充墙直接相连的,,，这是不合理的。特别当采用过小的周期折减系数，这种失真程度将明显增大。 2. 结构刚度突变 在建立整体计算模型时，往往由于楼梯细部尺寸未确定(如楼梯平台梁位置、标高等)，而没有考虑楼梯间的楼梯平台梁参结构空间|考试大|刚度的计算。如图2中的,轴上，两框架柱之间的半层处楼梯平台梁实际已经构成了框架梁，该处框架柱的线刚度显著增大，甚至形成短柱，恰恰这些地方正是结构刚度突变，并且填充墙影响较大而必须加强的部位。采用通常的周期折减系数的方法并不能准确有效的体现这种刚度变化和填充墙的不利影响。 结论和建议 international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central 1.由于结构计算模型未考虑非结构构件的刚度，目前，通过经验系数对计算周期进行折减，适当增大结构抵御地震作用的能力是必要的，也是可行的。抗震设计时，设计周期=计算周期×折减系数。 2.客观上，由于非结构构件(填充墙、现浇板、刚性地坪等)参与构成了实际建筑结构的刚度，但是非结构构件自身破坏时也耗散了地震能量，不可否认它参与了结构抗震。 3.折减系数的取值同样必须遵循概念设计原则，使用者必须首先弄明白，折减系数与哪些因素相关，哪些是该工程的主要影响因素。各因素在不同的实际工程、不同的变形阶段中的影响程度是不同的，应具体情况具体分析。 4.采用折减系数，应注意结构的 规则 编码规则下载淘宝规则下载天猫规则下载麻将竞赛规则pdf麻将竞赛规则pdf 性，刚度、质量(荷载)、非结构构件(如填充墙等)沿竖向分布和在平面分布的均匀性。 5.当主要考虑填充墙的刚度影响时，应根据填充墙的材料特性、开洞情况、沿竖向分布和在平面分布特点等综合考虑，一般多层钢筋混凝土框架结构按弹性计算的自振周期，其折减系数建议如下取值(墙长、多、开洞少而小者取小值): (1) 弹性(多遇地震)计算:空心砖填充墙体:0.7~0.9;轻质墙体:0.8~0.9. (2) 弹塑性(罕遇地震)验算:空心砖填充墙体:0.8~1.0;轻质墙体:0.9~1.0. international, Unicom international market, adapted future people on city of development needs, based Yu industry support, and traffic advantage, and Yangtze River culture, and ecological civilization, advantage, established city development target: radiation absorb Yangtze River upstream chuan Yunnan Guizhou of regional center, and international ecological landscape culture city. 2.3.2 economic development in Yibin city, goal 2020 GDP reached 300 billion yuan, the per capita GDP reached 58000 2030 regional GDP reached 800 billion yuan, the per capita GDP reached 138000. 2020 industrial structure adjustment in Yibin city as 9:56:35; 2030 industrial structure adjustment for the 6:47:47. Industrial output by 2020 of 510 billion yuan in 2030 and reach 1.2 trillion yuan. 2.4 of the urban population and land size 2.4.1 Yibin city, population size according to the different forecasting methods and the size of population environmental capacity check, the downtown main future population projections for the year are as follows: downtown main future population projections for the year (unit: million) forecast methods, 2020, 2030, balancing method for 130-150 table 2.4-1 170-190 ultra high speed development of relationship between economic and labour law development of 150 210 140 180 General develop 130 1.7 million people, resources and environment capacity check land population carrying capacity--280 water resources and population capacity-does not constitute a binding comprehensive prediction of ecological resources coupled--310 results of 140-180 in 2020, the actual resident population of about 1.4 million people; 2030 the actual resident population of about 1.8 million people. 2.4.2 the use of scale, Yibin city 2030 per capita index of urban construction land in the center of 100 square meters per person. Yibin city construction land standards and scale of table table 2.4-2 year population size (mass) land size (km2) land per capita ((km2/people) 2012 82.5 76.19 92.4 2020 140 140 100 2030 2030 Yibin 180 180 100 figure 2.4-1 figure 2.5 land-use planning layout of urban space in central