Outstanding Building
--Anti-seismic, Anti-typhoon Timberwork Building Design Competition
Instructions for designed works
 
 
 
Membership:
Dong Weibo;
Li Zhi;
Wu Yuxuan;
Guo Zhaoxia;
Zhu Wanrong;
Gong Xinyuan.
 
Advisor:
Gao Ying
 
Group’s Name:
Timberwork group,
Beijing Forestry University (BJFU)

Earthquake-resistant Design Instruction
1. Design basis
The structure design for this project has been carried out majorly based on the following national norms, standards and manuals:
Wood Structure Design Specifications                                         GB50005-2003
Load Code for Building Structures                                                  GB50009-2012
Earthquake Resistant Design Code                                                 GB50011-2010
Unified Standard for Reliability Design of Building Structures             GB50068 -2001
Classification Standard for earthquake fortification of Buildings  GB50223-1995
Use Manual of Japanese Wood
2. General situation of construction
The project is planned to be construct in Putian of Fujian Province, which covers a total construction area of 220m²: to be more specific, the area of the first floor is equal to that of the second one, namely 110m². The total height of the building is 9.12m; the height of the first floor is equal to that of the second one, namely 2.73 m; and the roof truss height is 2.67m. With the girder-column wood frame taken as the main structure, this building will adopt the reinforced concrete foundation. Moreover, characterized by reasonable pace division, convenient function and smooth moving line, this design is able to the demands of the residents.
3. Engineering geological profile
3.1 Geography
This project is located in the middle of Fujian coastal region: with an elevation less than 500m, the territory is mainly covered by hills; most of the underground soil is ooze; majorly covered by red and black soil, the land is fertile while the soil is loose.
3.2 Earthquake effect of the site
In accordance with the current national standard Earthquake Resistant Design Code GB50011-2010, the earthquake fortification intensity for the site in Putian region shall be 7 degrees. According to the design requirements of the competition, the earthquake fortification intensity for the project is 8 degrees, the design basic earthquake acceleration is 0.2g, the design earthquake group is the third group, and the construction site of the project belongs to the Category II site.
4. Load value
4.1 Live load: floor live load
According to the Load Code for Building Structures GB5009-2012, the load standard values and subentry coefficients for different categories of room are as shown in Table 4.1.
Table 4.1 Floor live load table

	Standard value (kN/m2)	Composite value coefficient	Frequent value coefficient	Quasi-permanent value coefficient
Living room, bedroom, cloakroom, corridor, staircase	2.0	0.7	0.5	0.4
Kitchen, recreation room	2.0	0.7	0.6	0.5
Bathroom, balcony	2.5	0.7	0.6	0.5
Laundry room	3.0	0.7	0.6	0.5
Dining room	4.0	0.7	0.7	0.7
Storage room, study	5.0	0.9	0.9	0.8

Roof live load: non-accessible roof, live load 0.5KN/m²
4.2 Dead load (including the dead weight and load of the filler wall line on the girder)
The overall weight of the structure is 96.67kN; according to the wall constitution and material property, the line load can be worked out:
Interior wall load of the door-free opening: 1.26kN/m
Exterior wall load of the door-free opening: 1.76kN/m
4.3 Wind load
According to the Load Code for Building Structures GB5009-2012, the project will adopt the once-in-fifty-year fundamental wind pressure in Putian region, namely Wo=0.7kN/m²; the ground roughness belongs to the Category B; the average wind speed is 2.6m/s; the wind direction is oriented to north and northeast; the values of the wind load shape coefficient, wind vibration coefficient and wind pressure height variation coefficient shall be determined by the Load Code for Building Structures GB5009-2012.
4.4 Snow load
Because Fujian Province is located in the south of China with an annual average temperature of 20.2℃, this project will not consider the snow load.
4.5 Earthquake action
According to the Earthquake Resistant Design Code GB50011-2010, the analysis and design parameters are as shown in Table 4.2.
Table 4.2 Parameters related to the earthquake action

Safety level of building structures	Level II
Coefficient for importance of structureγ0	1.0
Classification for earthquake fortification of building structures	Category C
Design working life	50 years
Building height	9.12m
Classification for structural system	Girder-column wood structure
Earthquake fortification intensity	8 degrees (Group Three)
Design basic earthquake acceleration	0.2g
Site classification	Category II
Characteristic cycle Tg	0.42s
Cycle reduction coefficient Tr	0.7
Damping ratio	0.05

5. Material properties
Table 5.1 Material properties [excerpted from Use Manual of Japanese Wood]

Name	Density (g/cm2)	Moisture content (%)	Elasticity modulus (MPa)	Damping ratio	Poisson ratio	Bending strength (MPa)	Compressive strength parallel to grain (MPa)	Tensile strength parallel to grain (MPa)
Dimension lumber of Douglas fir	0.54	12	10000	0.05	0.3	28.2	22.2	17.7
Dimension lumber of Cryptomeria fortunei	0.38	12	7330	0305	0.4	22.2	17.7	13.5

 

Table 5.2 Facing material properties

Name	Poisson ratio	Elasticity modulus(MPa)	Density (g/cm3)
OSB	0.25	1125	0.5
Gypsum board	0.24	3500	1.2

 
6. Main components
6.1 Girder
The girders are composed of the main girder and the secondary girder, the material for all of which is the dimension lumber of Douglas fir. The cross section size is shown as follows:
The main girder: 105*270mm
The secondary girder: 105*180 mm
 
6.2 Column
The column components adopted by the project are all the dimension lumber of Cryptomeria fortunei, the cross section size of which is 105*105mm; meanwhile, the column spacing is 1000mm.
 
6.3 Diagonal brace
The material of the diagonal brace component is the dimension lumber of Douglas fir, the cross section size of which is 105*45 mm.
 
6.4 Wall
Indoor partition wall: the spacer column will be set every 300mm between the girder-column frame; the gap between the spacer columns will be filled with the heat preservation cotton; the two sides of the girder-column frame will be covered with the gypsum boards to constitute the wall with a total thickness of 124mm;
Outdoor wall: the side of the exterior wall adjacent to the outdoor is composed of OSB, breathing paper, parting bead (with an interval of 450mm) and exterior wall stone in turn while the wall structure of the other parts is the same as that of the interior partition wall. The total thickness is 156.5mm.
To be more specific, the cross section size of the spacer column is 105*45 mm, the material of which is the dimension lumber of Cryptomeria fortunei; the cross section size of the parting bead is 20*100 mm, the material of which is the Cryptomeria fortunei; the thickness of the heat preservation cotton is 105mm; the thickness of the gypsum board is 9.5mm; the thickness of the OSB is 12mm; and the thickness of the exterior wall stone is 10mm.
 
6.5 Floor and ceiling
Floor: between the secondary girder and grille, the first floor and second floor will respectively be filled with thermal insulation material and sound insulation material, and then be laid with OSB with a thickness of 12mm and the strengthened solid wood composite floor board;
Ceiling: under the secondary girder, the OSB with a thickness of 12mm and the gypsum board with a thickness of 9.5mm will be laid.
 
6.6 Roofing board
The rafter with a dimension of 105*45 mm and the purlin with a dimension of 105*45 mm will be laid on both sides of the roof ridge; meanwhile, the basic frame will be further laid with OSB with a thickness of 12mm, five waterproof layers and solar panel.
 
7. Structural analysis
According to the Wood Structure Design Specifications GB50005-2003, as well as the design and construction requirements stipulated by the related design manuals, the Google SketchUp software will be adopted to design the girder-column wood structure skeleton model. In addition to the foundation bearing capacity structure constituted by girder and column, the project will additionally set up the diagonal brace so as to improve the overall earthquake-resistant performance of the building. The diagonal brace will adopt the dimension lumber of Douglas fir in a dimension of 105*45mm, which is in the “X-shaped” structure: the diagonal brace will be distributed at the four corners of the house and the places inside the house carrying a large stress, which can enhance the node load capacity and the overall deformation resistant capability.
The structure skeleton model is as shown in Figure 7.1.
 
The structure analysis software of the project will adopt the building structure design software SAP2000 provided by CSI Company of the United States to construct the girder-column wood structure skeleton model. By imposing vertical load, wind load and earthquake load to the overall structure, the simulation and calculation will be carried out over the overall structure under ten different working condition combinations to analyze the stress-carrying and deformation of the building under different working condition combinations (the specific load working condition combinations shall refer to 7.1).
The analysis model of SAP2000 is as shown in Figure 7.2.

7.1 Load working condition combination
The analysis will be carried out in accordance with the Load Code for Building Structures GB50009-2012, the Wood Structure Design Specifications GB50005-2003, and the load working conditions probably taking place in the design and the combination will be divided into three kinds of limit state:
1. The limit state of the bearing capacity under the normal circumstance (basic combination CBJ);
2. The limit state of the normal use under the normal circumstance (characteristic combination CBB);
3. The limit state under the circumstance of earthquake (accidental combination CBO).
To select the combination for calculation, the design and analysis shall be carried out for each most unfavorable combination.
7.1.1 Basic composition
As for the basic composition, during the design calculation, the project has majorly adopted the three kinds of load combinations as shown in Table 7.1.

Table 7.1 Table for the basic combinations

Serial number of combination	Combination form
CBJI	1.2 dead load+1.4 live load
CBJ2	1.35 dead load+1.4*0.7 live load+1.4 wind load
CBJ3	1.35 dead load+1.4 live load+1.4*0.6 wind load

 
7.1.2 Characteristic combination
As for the characteristic composition, during the design calculation, the project has majorly adopted the three kinds of load combinations as shown in Table 7.2.
Table 7.2 Table for the characteristic combinations

Serial number of combination	Combination form
CBB1	1.0 dead load+1.0 live load
CBB2	1.0 dead load+0.7 live load+1.0 wind load
CBB3	1.0 dead load+1.0 live load+0.6 wind load

7.1.3 Accidental combination
As for the accidental composition, during the design calculation, the project has majorly adopted the four kinds of load combinations as shown in Table 7.3.
Table 7.3 Table for the accidental combinations

Serial number of combination	Combination form
CB01	1.0 dead load+0.5 live load+1.0 earthquake load-Wx
CB02	1.0 dead load+0.5 live load+1.0 earthquake load-Wy
CB03	1.35 dead load+1.4*0.5 live load+1.3 earthquake load-Wx
CB04	1.35 dead load+1.4*0.5 live load+1.3 earthquake load-Wy

 
7.2 Component analysis
7.2.1 Checking calculation over the maximum axial tension (P_t) and bearing capacity of the component
By comparing the maximum axial force and its bearing capacity of the component under the each working condition combination, the maximum axial force worked out by the overall model SAP2000 is as shown in Table 7.6.
Table 7.6 Table for the maximum axial tensile under different working condition combinations

Working condition combination	Tension Ptmax
	Component name	Type	Axial force size (kN)	Cross section area (mm2)	Tensile strength (MPa)
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace
		Diagonal brace

Based on the above table, it can be known that the maximum tensile strength parallel to grain of the component is 4.341 MPa, which takes place on the working condition combination with the participation of earthquake in CBO 4, namely in the direction of Y. The tensile strength parallel to grain of the dimension lumber of Cryptomeria fortune is 13.5 MPa while that of the dimension lumber of Douglas fir is 17.7MPa: in the above-mentioned ten working condition combinations, the maximum axial force for each component is less than the bearing capacity limit values stipulated by the specification and the design manual; therefore, the components adopted by the project have enough safety reserve to withstand the load actions from the outside and their own.
 
7.2.2 Checking calculation over the maximum axial pressure (P_c) and bearing capacity of the component
By comparing the maximum axial force and its bearing capacity of the component under the each working condition combination, the maximum axial force worked out by the overall model SAP2000 is as shown in Table 7.7.
Table 7.7 Table for the maximum axial pressure under different working condition combinations

Working condition  combination	Pressure Pcmax
	Component	Type	Axial force size (kN)	Cross section area (mm2)	Tensile strength (MPa)
		Column
		Diagonal brace
		Column
		Column
		Diagonal brace
		Column
		Column
		Diagonal brace
		Column
		Diagonal brace

Based on the above table, it can be known that the maximum compressive strength parallel to grain of the component is 7. 031MPa, which takes place on the working condition combination with the participation of earthquake in CBO 4, namely in the direction of Y. The compressive strength of the dimension lumber of Cryptomeria fortune is 17.7 MPa while that of the dimension lumber of Douglas fir is 22.2 MPa: in the above-mentioned ten working condition combinations, the maximum axial force for each component is less than the bearing capacity limit values stipulated by the specification and the design manual; therefore, the components adopted by the project have enough safety reserve to withstand the load actions from the outside and their own.
7.2.2 Interlayer displacement angle
The maximum interlayer displacement under different working conditions is as shown in Table 7.9.

Table 7.9 The maximum interlayer displacement under different working conditions

There is no regulation in our nation’s Earthquake Resistant Design Code GB 50011-2001, the new version of Earthquake Resistant Design Code GB50011-2010 and the Wood Structure Design Specifications GB 50005-2003 over the interlayer displacement angle of the wood structure building. In the Earthquake Simulation Shaking Table Test over the Full-Scale House Model with Two-Storey Light Wood Structure, the scholars of Tongji University draw the test result and conclusion that “in the earthquake of 0.2g, the maximum interlayer displacement angle of the building with a symmetrical layout structure is 1/250”. From the Table 7.9, it can be known that the interlayer displacement of structure under the working condition combination with the participation of earthquake in CBO 3, namely in the direction of X, will be maximized, the value of which is 11.24mm so that, the interlayer displacement angle of the project structure will be: u/1=11.24/6000≈1/534<1/250. Therefore, the structure can meet the requirement over the interlayer displacement angle limit stipulated by the test result in the references.
 
8 Analysis and summary
By adopting the SAP2000 software, this project has managed to carry out modeling over the girder-column wood structure, as well as to simulate and analyze the strength and stability of the structure under ten working condition combinations. The internal force analysis and deformation result under different working condition combinations have indicated that the compressive strength parallel to grain and the tensile strength parallel to grain of the components adopted for the girder-column wood structure building by the project are all less than the bearing capacity limit values stipulated by the specification and the design manual; meanwhile, the maximum interlayer displacement of the overall structure is less than the interlayer displacement limit under the earthquake of 0.2g.
Therefore, with reasonable layout, appropriate rigidity and large safety reserve, the overall structure of this project can meet the requirements of the corresponding specification s and standards. 

世聯(lián)翻譯-讓世界自由溝通！專業(yè)的全球語言翻譯供應(yīng)商，上海翻譯公司專業(yè)品牌。絲路沿線56種語言一站式翻譯與技術(shù)解決方案，專業(yè)英語翻譯、日語翻譯等文檔翻譯、同傳口譯、視頻翻譯、出國外派服務(wù)，加速您的全球交付。 世聯(lián)翻譯公司在北京、上海、深圳等國際交往城市設(shè)有翻譯基地，業(yè)務(wù)覆蓋全國城市。每天有近百萬字節(jié)的信息和貿(mào)易通過世聯(lián)走向全球！積累了大量政商用戶數(shù)據(jù)，翻譯人才庫數(shù)據(jù)，多語種語料庫大數(shù)據(jù)。世聯(lián)品牌和服務(wù)品質(zhì)已得到政務(wù)防務(wù)和國際組織、跨國公司和大中型企業(yè)等近萬用戶的認可。