Since the reform and opening up, China's economy has been developing at a high speed, and large-scale urbanization is underway, and this process will continue for 20~30 years. During this period, various industries in various fields are in high development stage, in the construction of a large number of permanent buildings, structures and roads, bridges and transportation facilities, etc., and the future use of the process requires a large number of temporary buildings and their supporting, in addition to the long-term need for field work, open-air work in the industry, in the case of emergency needs, disaster relief, in tourism, festivals and the peak of the flow of people need to meet the different requirements of the temporary housing. Temporary housing. So a variety of temporary buildings came into being, with the progress of the times, the improvement of labor conditions, the need to build a harmonious society, the state of the temporary construction of the safety, application and improvement of living conditions have high requirements. At present, the domestic temporary construction of various industries and regions are different, to the construction industry and urban transportation construction, for example, construction site construction site for workers' dormitories, offices, canteens and LunKu, etc., the temporary construction of housing, before the northern region more than a small angle steel tent with a simple shed, and then improved to 2-3 layers of small angle steel and cement board composed of cement board room; the south more bamboo shed; and the need for long-term The long-term need for wild open-air operation of the containerized activity room. Now more and more lightweight steel structure modular house, lightweight steel structure modular house in Beijing construction engineering construction site temporary housing increased year by year, currently accounts for about half of the total amount of more than one half; in Shenzhen, Guangdong, building construction sites, urban rail transit construction site temporary housing almost all lightweight steel structure modular house. Because the light steel structure combined housing as a temporary housing than other types of temporary housing has many advantages, so the light steel structure combined housing in the application of temporary construction accounted for a larger and larger proportion.
1). Characteristics of Light Steel Structure Combined House
Light steel structure combined house generally refers to the use of light H-beam, cold-formed thin-walled steel, round steel, small angle steel and compression molded steel plate, sandwich plate composed of 1 to 3 layers of temporary buildings. This kind of light steel structure combined house is the simplest and industrialized light steel structure house.
Light steel structure modular house is divided into plate structure, frame support structure, frame structure and box unit structure according to different structural types. Light steel structure modular house has the following characteristics:
(1). Light weight: the weight of modular house is about 15~30kg/m2.
(2). Assembly is simple and fast: all the components of the house, plates are prefabricated in the factory, transported to the site using bolts, self-tapping screws, pull rivets and other connectors assembly. The construction speed of the house is very fast, according to the different types of houses, generally 1 worker can install 20~50m2 in 1 day. A two-storey 200m2 combined house can be installed by 6 workers in a day and a half, and can be put into use right away, it is the industrialized degree of steel structure building.
(3). Design standard stereotypes, flexible and diversified combinations; factory production of components, high precision processing, good quality.
(4). The house can be disassembled, can be relocated, transportation and assembly is simple. A car can be loaded and shipped with about 500 square meters of combined houses.
(5). Lightweight steel structure modular house is lightweight, simple foundation with less workload and good anti-seismic performance.
(6). The modular house is an environmentally friendly building, and there is no construction waste during the construction.
(7). It can be sold or leased, providing users with a variety of choices and services.
Due to the above advantages, light steel structure modular house is widely used in temporary buildings in construction engineering, railroad and highway construction, petrochemical industry, water conservancy construction, military engineering and earthquake relief. In addition, they are widely used in temporary office buildings, temporary dormitories and temporary small factories and warehouses, etc.; in commercial buildings such as stores, newspaper offices, restaurants, telephone halls, etc.; in tourist buildings such as vacation houses; in traffic posts, toll booths and other transportation facilities, as well as in sanitation buildings, etc.
The demand for temporary construction in the construction market alone is very large. With the national standardization of the temporary construction market housing, will greatly accelerate the process of dismantling the combination of housing to replace other types of temporary construction. Demolition type activity room will be in the next few years will usher in the golden period of its development. In addition, due to the rise in labor costs, the demand for box structure modular houses will rise gradually. At the same time, the box structure combination house in the tourism market and other areas of application will also be expanded.
2). The development and application of light steel structure combined houses
Various kinds of temporary houses began to rise in the 1980s, and after more than 20 years of rapid development of temporary houses, cement board houses represented by Wujiang and Langfang movable houses, light steel structure assembled movable houses represented by Elegant Company and Yungdong and Chengdong, mobile box houses represented by Sanhe Lianshan, RV type houses represented by Zhongtian RV, light steel structure assembled houses represented by Baotian RV, and mobile box houses represented by Baoji RV, and mobile box houses represented by Baoji RV. On behalf of the room car type housing, Baosteel color steel development company on behalf of the tourism villa house, into the mobile home industry has been the size of thousands of enterprises, the larger manufacturers are elegant, Rongdong, Chengdong, Hengxin and so on.
Elegant integrated housing Co., Ltd. is a Shenzhen China Nanshan Development (Group) Co., Ltd. Holdings of joint-stock enterprises, the registered capital of 135 million yuan, with a total investment of 700 million yuan. The company is committed to the development and operation of new integrated housing, advocating the design and application of temporary buildings to achieve standardization, modularization, generalization, and the realization of factory mass production. Elegant integrated housing with energy saving and environmental protection, easy to dismantle the product advantages of repeated use of multiple turnover, is to lead the development of the temporary construction industry into a new industry that can provide efficient, environmentally friendly, economic industrialized products and supporting services. The company is headquartered in Shenzhen High-tech Park, with regional headquarters in Beijing, Shanghai, Fuzhou, Wuhan, Chengdu and other places, and supporting large-scale production and distribution bases, with an annual production capacity of 5 million square meters, sales and service network covering dozens of key cities across the country, and has formed a nationwide business pattern. The company's products have been exported to Southeast Asia, the Middle East, Africa, South America and other regions. The company has become China's light steel structure modular housing production scale and output, sales and leasing manufacturers, sales in 2006 reached 1 billion yuan, building area of more than 3 million square meters. 2007 sales will reach 1.4 billion yuan, building area of about 4 million square meters. The company's light steel structure combination of housing in the Beijing Olympic venues, Guangzhou Metro, Chengdu, the new construction of the temporary construction of housing in a large number of applications.
Rongdong Mobile House Co., Ltd. was established in 1988 as a joint venture between the First Construction Engineering Company of Fuzhou and Tokai Leasing Co., Ltd. of Japan, which introduced a full set of advanced technology and equipment of Japanese modular houses, and has branch offices and factories in Zhangzhou, Beijing, Shanghai, and Xi'an, with a registered capital of RMB 100 million yuan. The company's registered capital is RMB 100 million, and it is a movable house company with larger registered capital, more outlets, high technology level and stronger strength in China. Its houses are widely used in coastal Fujian, Beijing, Shanghai and Northwest China.
Beijing Chengdong Housing Manufacturing Co., Ltd. is the earliest professional manufacturer of mobile homes in China. The company has strong research and development capabilities, advanced technology, high productivity per capita, and its products are sold to more than ten overseas countries, and it is one of the enterprises with foreign trade export business performance in the domestic mobile house industry. In Beijing, the fiftieth anniversary of the founding of the military parade training room, Xiaotangshan emergency hospital and the construction of the Qinghai-Tibet Railway in the construction of a large number of applications in the temporary housing, the quality of its unanimously praised. 2006 sales amounted to 160 million yuan, sales in 2007 will reach 220 million yuan.
3). Light steel structure combined housing market demand forecast
The development of domestic temporary housing market in the past five years shows that its market capacity, market maturity and the overall level of local economic development is directly proportional. According to the relevant information, the demand for light steel structure modular houses in the construction industry in the next five years is as follows: (2 square meters per capita of the number of employees in the construction industry to predict the total area of demand for the construction industry for the construction of houses)
Note:
(1). According to the national "Eleventh Five-Year Plan" and Vision 2010, the average growth rate of the construction industry is 7.5%;
(2). Through 2006, the beginning of 2007 on the country's several major regions to carry out a more detailed market research, the past two years due to the regions of the temporary building requirements become more stringent and activities to further reduce the price of the room, the activity of the room utilization rate has been further improved, a preliminary understanding of the region's lightweight steel activity of the room utilization rate is as follows: Guangzhou Shenzhen as the representative of the South China region board room utilization rate of 65%, represented by Shanghai as the representative of the East China regional boarding house utilization rate of 40%, to Beijing, Tianjin as the representative of the North China regional boarding house utilization rate of 40%. It can be seen, the Yangtze River Delta, Pearl River Delta and Beijing and Tianjin as the center of the economically developed areas of light steel activity house utilization rate have reached more than 40%, but in the western economically underdeveloped areas of light steel activity house utilization rate is lower, so the comprehensive national point of view, the existing major regions (including South China, East China, North China, Northwest China, Southwest China, Central China and Northeast China, including) of the comprehensive utilization rate of light steel activity house should be in the 30% or so. In order to more convenient for the next five years of the market forecast, we will be young steel activity house in 2007 to determine the utilization rate of 30%, we will be the national market in the next three years of the use of lightweight steel activity house growth rate of 5%, the next two years is set at 4%, for which we can derive the next five years of the demand for the area of the activities of the board. 2. Foreign research and application of light steel structure combined housing
In the United States. Europe. Japan and other places light steel structure combination of housing is widely used, light steel structure combination of housing is also a lot of professional manufacturers, some of them are also very large.
1). ALGECO is the sales and leasing company of light steel structure modular house in France and even in Europe. There are factories and branches all over France, dozens of warehouses and more than 1 million square meters of housing stock. Sufficient housing stock and a large transportation fleet ensure the rapid construction and use of housing, thus obtaining good economic and social benefits.
ALGECO's lightweight steel modular houses are 1 to 3-story houses made up of box units. The interior of the room can be made up of several boxes to form a large flexible space, and can also be partitioned into small rooms with lightweight panels. The modular house can be equipped with external corridors, external staircases or internal staircases. The single box unit is composed of lightweight H-beam, channel steel, square steel tube base; columns, longitudinal beams and cross beams are made of cold-formed thin-walled steel with special shapes; the roof is made of colorful compression steel plate, thermal insulation materials and color steel ceiling panels; and the wall panels are made of color steel sandwich panels. In the design of column section, we have considered to set up the water fall pipe and electric wire. ALGECO has researched and developed many kinds of product series according to the requirements of the customers, for example, 1000 series is the single economic modular house; 3000 series is the modular house that can be stacked; 7000 series is the new type of box unit modular house, according to the different dimensions of the single box unit, it is divided into 11 kinds of types, among which, the width has 2 kinds. There are 2 kinds of width: 2.44m, 2.93m; height of 2 kinds: 2.65m, 2.84m; length of 5 kinds: 4.40m, 6.21m, 7.35m, 8.82m, 11.87m; France ALGECO company's lightweight steel structure of the combined housing is widely used in a variety of temporary offices, accommodations, hospitals, classrooms, gymnasiums and warehouses, such as storage; for the commissary, kiosks and ticket offices, and other commercial buildings; restrooms, kiosks and ticket offices, and other commercial buildings, restrooms, and other commercial buildings. commercial buildings; restrooms, security and other special rooms; for all kinds of emergencies, disaster relief and other rooms. It can also be used to build high-grade combined houses with internal and external decoration according to customers' requirements.
2). Japan has a lot of light steel structure combination of professional manufacturers of housing, including NAGAWA is a box unit system of light steel structure combination of housing production, sales, rental of professional manufacturers, is the industry's first. Nippon Tokai Leasing Co., Ltd. is a professional manufacturer of box unit and frame-supported system light steel structure modular house production, sales and leasing, entered into China in 1988, and has successively established its business in Fujian, Shanghai, Beijing. Shanghai, Beijing, Xi'an and Dongguan. Xi'an, Dongguan and other places to invest in the establishment of factories and companies.
(1). Japan NAGAWA company light steel structure modular house 1996 sales of 20.1 billion yen, in the country with 22 factories, 47 sales offices, 2,300 agents, the country's permanent showroom 57 places. There are three main types of NAGAWA modular houses:
(a). (a) Single box unit: There are 6 kinds of box units with different sizes and specifications, which can be assembled into various types of single-story. Two-story combination house;
(b). Rows of box structure integrated housing: standard box unit size: length 5.4m, 5.6m, 7.2m three kinds; width 2.33m; height 2.697m; standard box unit is used for the end of the house. Center. Doors and windows. With cupboards. With a bathroom. Standard units with internal and external staircases, etc. for each part of the house. The roof of a modular house. The interior of the exterior walls. Ceiling. Floor. Doors, windows, electrical appliances and other parts of the structure of a unified standard stereotypes. 8 kinds of standard box unit can be composed of a variety of functions of the single-storey. 8 kinds of standard box units can be composed of various functions of single-story and two-story combination houses.
(c). According to the customer's requirement design and processing of high-grade modular house: the structure of modular house is still a box unit, only the internal and external decoration. Cabinet. Bathroom and other high-grade products, can provide single-story. We can provide single-story and two-story modular houses. NAGAWA's modular houses are widely used in temporary offices, offices, simple warehouses and storage rooms in construction sites; various simple stores for large-scale events; and temporary housing for disaster relief such as typhoons and earthquakes. High-quality modular houses are widely used for vacation homes, offices, shops, and so on. The high-grade modular houses are widely used for vacation houses, offices, stores, and so on.
Japan's NAGAWA combined house has the following advantages: quick on-site installation, simple thirty minutes, complex installation can be completed within a day; combined house can be dismantled can be relocated, and handling is not affected by rain and snow, fast and economical. The rich and novel appearance modeling of the modular house can meet the requirements of different customers; light steel structure modular house has good anti-seismic and wind-resistant properties. Good wind resistance, high strength and durability. Japan NAGAWA company's modular house with its more than 30 years of performance, quality of ISO9001 standard certification, modular house is the first in the industry in Japan, the company is a publicly traded company. So get the customer's favor.
(2). Ltd. prefabricated assembled lightweight steel structure modular housing can be made into 1 ~ 3-story houses. The structure type is box structure or frame supported structure.
(a). Box unit structure system: the columns of the box unit are made of square steel tubes, and the beams are made of light H-beam, channel steel, cold-formed steel, etc. The roof and walls are made of steel tubes, and the beams are made of light H-beam, channel steel, cold-formed steel. Roof and wall are made of sandwich panel. We can design various sizes of standard box units according to customers' needs. For example, the length is 5.7m, the width is 2.33m, the height is 2.698m. In addition, according to the distance, transportation conditions and freight and other factors, the box unit can be made into two kinds of integral type and folding type, one kind of box unit housing all done in the factory, the whole is transported to the site unloading trucks and put it can be used; one kind of folding type box unit structure, that is, the top and both ends of the box unit are processed into a folding, the bottom, the side panels, doors and windows and all the accessories. Side panels and doors and windows and other accessories are all prefabricated, because they can be overlapped and stacked a truck can transport 3~4 box units, greatly saving the freight. The workload for on-site assembly is also small.
According to the different requirements of customers, the box unit structure can be composed of single-story single, horizontal and vertical rows of combined houses; two-story horizontal and vertical rows of combined houses, and configured with a variety of internal and external staircases.
(b). Frame-supported structural system: standard stereotypes of combined houses, length and width (span) direction are K as a modulus, 1K = 1820mm; height direction P as a modulus, 1P = 895mm (the width of the wall panels). The dimensions in the length and width directions are multiples of the modulus K=1820mm except for the ends. Width: 1.5K=2805mm, 2K=3715mm, 2.5K=4625mm, 3K=5535mm, 4K=7355mm, 5K=9175mm. gable height of single-story modular house: 2640mm (2.5P), 3085mm (3P), 3535mm (3.5P), 3980mm (4P), two-story Combination house gable height: 5325mm (5.5P), 5770mm (6P), 6665mm (7P), 7560mm (8P), three-storey combination house gable height: 8455mm (9P), 9355mm (10P). We can also provide non-standard specifications of modular house according to customers' requirements.
The columns of the combined house are made of 2C or 3C cold-formed thin-walled steel sections; the combined house can have double-slope roof or single-slope flat roof; the triangular roof frame of the double-slope roof is made of cold-formed thin-walled steel; the single-slope flat roof can be made of 2C cold-formed thin-walled steel I-beam sections or light welded H-beams; and the truss beams of the floor are also made of C-cold-formed thin-walled steel processing. Roof wall according to the need and cost can choose several construction practices. Roofing can be two layers of colored compression steel plate in the middle of the glass wool, there are also sandwich panels, the wall using sandwich panels. Doors and windows using aluminum alloy doors and windows. 3. Problems in the application and suggestions for improvement
(1). Standardize the market, strengthen the quality management, to ensure the safe use of housing
As mentioned above the need for temporary construction is large and increasing year by year, is a considerable market. However, at present, the domestic temporary construction market is relatively chaotic, housing good and bad, safety and quality accidents occur from time to time. Some temporary construction in the use of the sudden collapse, some blown down by the wind, some fire burned, some in the installation or dismantling collapsed, etc., resulting in casualties and property losses, so to ensure the safe use of temporary construction of housing is imminent.
Practical experience at home and abroad has proved that lightweight steel structure combined housing is a new technology and new products with great development|examination of the future, but due to the application of time is not long in our country, in the design standards and processing quality management deficiencies, so in the use of some of the problems that arise, the main problems are: leakage of roofing, columns, beams, and roof racks, such as the processing and installation of steel components of poor quality steel components corrosion problems, fire prevention problems, etc.. Fire prevention problems and so on. These problems and light steel structure combined housing design and processing is not standardized have a great relationship.
(2). Solve the problem of design basis and product standard as soon as possible
Light steel structure modular house belongs to temporary building, according to the national standard "Unified Standard for Reliability Design of Building Structures" GB50068-2001, the modular house design life is 5 years, the structure in the stipulated design life should meet the requirements of safety, suitability, durability and other functional requirements, in order to ensure that the structure has the stipulated reliability, in addition to the design of the structure should meet the requirements of safety, suitability, durability and other functional requirements. In order to ensure the reliability of the building structure, in addition to the necessary design calculations, should also be material performance, construction quality, use and maintenance of the corresponding control. The specific requirements for control should be in line with the special provisions of the relevant design and construction standards. At present, there are no special standards, regulations and reference atlases for light steel structure combined houses for temporary construction in China. If it is validated strictly according to the existing regulations and norms, most of its design and construction are unqualified, especially the 3-story houses. At present, this kind of housing is in the design of random or missing, market confusion product quality is difficult to guarantee. Only the Beijing Municipal Construction Committee has prepared the "construction project construction site temporary housing technical regulations (light steel structure part)" DBJ01-98-2005, the China Association for Standardization "disassembled movable house" CAS154-2007, these two standards are still to be perfected, most of the domestic combination of housing is still in the temporary building is not attached importance to the state of unmanaged, so the use of collapsed, fire So the use of collapse, fire, wind damage occurs from time to time, and some of them are also very serious resulting in casualties and property losses. So in order to meet the requirements of domestic use and export, as soon as possible to organize the preparation of the Ministry of Construction light steel structure combined housing product standards and standard atlas is very necessary.
(3). Discussion on fire prevention of light steel structure modular house
The fire prevention of light steel structure modular house should also comply with the relevant provisions of the national standard "Code for Fire Protection of Building Design" GBJ16-87 (2001 edition). Light steel structure modular housing is a temporary building, can be in accordance with the provisions of Article 5.1.1 of the Code, the fire resistance level of four, the maximum number of permitted layers of 2 layers, fire protection sub-district allowed | exam large | length of 60 meters, each layer of the permitted floor area of 600 square meters. Remarks requirements for schools, canteens, food markets, nurseries, kindergartens, hospitals, etc. should not exceed one floor. In addition, in accordance with the provisions of the code section 2.0.1, Table 2.0.1, for the fire resistance level of four buildings of its components of the combustion performance and fire resistance limit: multi-storey columns for the incombustible body, the fire resistance limit of 0.5 hours, a single layer of columns can be a combustible body; beams for the incombustible body, 0.5 hours; floor slabs for the incombustible body, 0.25 hours; the roof load-bearing components, evacuation staircases and suspended ceilings are all combustible body; Walls: non-load-bearing external walls, partition walls on both sides of evacuation aisles and room partition walls are incombustible, 0.25 hours. According to the provisions of the current lightweight steel structure of the combined housing in the number of layers on the 3 layer is not in line with the fire requirements; individual as a school, cafeteria, there are more than one layer; 2 layers of 3 layers of combined housing steel columns and steel beams without a suspended ceiling fire-resistant limit of less than 0.5 hours requirements; other can meet the requirements. For this reason, it is possible to make fireproof treatment for the steel columns of the 2-storey combined houses, such as applying fireproof coating or covering with fireproof boards. In addition, should strictly comply with the provisions of the specification of the permitted length of the fire interval of 60 meters and each layer of the permitted floor area of 600 square meters of the provisions of the number of evacuation stair spacing can not be arbitrarily reduced in order to save the line.
(4). Actively carry out research and development of light steel structure combined housing
On the basis of learning advanced foreign technology, combined with China's specific conditions, research and development of series products suitable for different regions and industries, improve the standardization of light steel structure combined housing, stereotypes and factory level, to ensure the quality of housing. In addition, the flexible operation of rentable and saleable is in line with the policy of energy saving, emission reduction and civilized construction, which is also worth promoting.