建筑防护方案问题的讨论.doc

黑龙江工程学院本科生毕业设计
建筑防护方案问题的讨论

    摘要：本文通过对建筑消防设计有关问题的探讨，总结地下建筑在消防设计中应注意的几个问题。
    关键词：建筑  防火、防烟分区  安全疏散  装修材料不燃化
地下建筑消防工作应重视火灾的预防和早期的火灾的扑救，立足于建筑内部防火设施的完善。因而，在地下防火设计需要考虑的问题很多，如总平面布置、建筑物的耐火等级、防火分区、防火间距、安全疏散、消防给水、通风空调和电器防火等方面的内容。同时，还要根据地下火灾的特点，采取控制火源、控制火灾发展蔓延、安全疏散、火灾自动报警和灭火装置等一系列消防措施在地下建筑防火设计中应注意考虑以下几个主要问题：
     一、建筑的使用功能和建筑规模
    1、对于地下建筑的总平面设计应根据城市的总体规划，合理确定其位置、防火间距、防火通道和消防水源。
    2、甲、乙类生产和贮存物品不应设在地下建筑内，这是我国现行《建筑设计防火规范》中规定的。在《人民防空工程设计防火规范》中还规定了“人防工程内不应设置高压锅炉房、氨冷冻站和甲、乙类的生产车间、物品库房。”“人防工程内严禁采用液化石油气和闪点小于60度的液体作为燃料。”一般来说，甲、乙类易燃易爆物品着火后燃烧异常迅速而猛烈，甚至发生剧烈爆炸，地下建筑发生爆炸后，灭火困难。更为严重的是，一些封闭式地下建筑发生爆炸事故后，由于地下建筑泄压困难，冲击波会把建筑物摧毁，造成的后果是极其严重的。因而，要引起足够的重视。
    3、人员密集的公共建筑应设在地下一层。如影剧院、地下游乐场、溜冰场等歌舞娱乐场所，只应设在地下一层，室内地坪与室外出入口地面高差不应大于10米；商业和服务行业为主的流动人员较多地下商街应设在地下一层，而且应该浅埋。从我国的具体情况来看，从人员疏散安全的观点出发，人员密集的建筑应该浅埋。另外，超出两层的地下建筑，应设防烟楼梯间。除此之外，《人民防空工程设计防火规范》中还规定：“人防工程内不应设置哺乳室、幼儿园、托儿所及残疾人员工作的场所。商场营业厅不宜设置在地下三层及三层以下。”
    二、建筑的防火、防烟分区
    为了保证一旦发生火灾、能使火灾控制在限定的范围内，对于大型地下建筑，由于人员密集、可燃物较多或火灾危险性较大，应划分成若干个防火分区，这对于防止火灾的扩散和蔓延是非常必要的。
   建筑防火分区的划分，应比地上建筑要求严格些。根据《人民防空工程设计防火规范》（2001版）最新修订版，“当地下商店总建筑面积大于20000平方米时，应采取防火墙进行分隔，且防火墙上不得开设门窗洞口。”但2006版《建筑设计防火规范》对地下商店的要求略有放宽：“当地下商店总建筑面积大于20000平方米时，应采用不开设门窗洞口的防火墙分隔。相邻区域确需局部连通时，应选择采取下列措施进行防火分隔：一是采用下沉式广场等室外敞开空间；二是采用防火隔间；三是采用避难走道；四是采用防烟楼梯间，楼梯间与前室的门均应采用甲级防火门。”视建筑的功能，每个防火分区面积一般不宜大于500平方米，但设有可靠的防火、灭火设施，如自动喷水灭火系统时，可以放宽，但不宜大于1000平方米，在人防工程的地下影院、礼堂的观众厅防火分区最大允许使用面积不应超过1000平方米。同时，当设有自动灭火设备，其最大允许使用面积也不应增加。商业营业厅、展览厅等，当设置有火灾自动报警系统和自动灭火系统，且采用A级装修材料装修时，防火分区最大建筑面积不应大于2000平方米。娱乐场所应采用耐火极限不低于2.00小时的隔墙和1.00小时的楼板与其它场所隔开，一个厅、室的建筑面积不应大于200平方米。当墙上开门时，应设置不低于乙级的防火门。地下街的墙应为防火墙。防火墙间的建筑面积不宜大于500平方米。
    建筑内的防火墙，同样要用混凝土或砖砌筑，并具有不低于3小时的耐火极限。防火墙上开设的门，通常要采用甲级防火门，且必须可以双向手动开启的，具备自动开闭功能。同时，可以有限制的采取防火卷帘来进行防火分隔，并满足其耐火极限要求。
防烟分区的设计应结合防火分区的设计进行。一般来说，防烟分区不宜跨越防火分区。一个防烟分区的面积不应大于500平方米。防烟分区的形成，一般有隔烟壁、防烟卷帘防火门、排烟机械等。
     三、安全疏散
     在地下建筑物中发生火灾、人员的安全疏散是十分重要的问题。
    1、疏散时间是安全疏散设计的基本指标。失火后使人员能在较短的时间内通过疏散口从危险地点疏散到安全地点——地下建筑外或避难处。因此，到安全出口的最大距离、通道的宽度、出口的数目，都必须从安全疏散时间的需要出发来确定。日本消防部门认为地下建筑疏散时间应在3分钟之间，若3分钟还不能从火灾区疏散到安全地带，人员就很危险。我国有关部门在几个地下电影院做过几次实验，从人员疏散到人员疏散结束大体3-4分钟（有的门没打开），其中大多数的建筑物的出入口设计宽度都能满足。对于地下建筑来说，由于烟气的危害性大，在考虑人员安全疏散时，其疏散时间应从严控制。参考地面建筑的疏散时间及国外地下建筑的疏散时间，我国地下建筑疏散时间应控制在3分钟之内。
     2、关于疏散速度的问题，这是安全疏散的一个重要指标。这个问题因建筑物功能不同，人员组成不同，照明条件不同，其差别比较大。地下建筑在无自然采光的条件下，疏散速度会小些，尤其是火灾时，由于正常电源被切断，在事故照明幅度小的情况下，疏散速度会小的多，因此，取值时应考虑这些不利因素。
     3、建筑必须有足够疏散宽度。当人员密度不大时，可按不少于两个直接对外出口的原则进行考虑。人员较多或规模较大的地下建筑，安全出口的数量要相应的增加，如国外地下停车场，一般要设5-6个安全出口；高峰时人数达1500人的地下车站，设宽2.4米的出口6个。
同时，在设计中还要考虑到安全疏散的距离。安全出口不宜按不同的方向设置。其距离应满足房间内最远点至最近安全出口的距离不宜超过15米；房间门至最远安全出口的最大安全距离，一般工程应为40米，旅店为30米，医院为24米。在地下街内的疏散应考虑，由各单位到外疏散楼梯的距离最好不大于20米；停车场、汽车库、仓库、变电所等单位；出口距离可不大于30米，但其中停留较多人员的部分，不宜大于20米。
     对于用地下道连接地上建筑的地下室及地下道两侧布置营业的单位时，地下道的宽度可采用6米；单侧布置营业单位时，可采用5米，当然在街区规模很小、火灾危险性不大、疏散中没有障碍的条件下，也可采用3米。设计地下道时，考虑到事故条件下紧急疏散的安全，在地下道内不要形成死胡同。
     四、建筑内部装修的不燃化
     建筑的内部装修不燃化，是关系到地下建筑发生火灾，人员安全疏散和火灾扑救的大问题，根据《人民防空工程设计防火规范》中规定，“除地下铁道、公路隧道及剧场等外，其他地下建筑耐火等级为一级，其出入口地面建筑的耐火等级不应低于二级”。平时利用的地下工程，其防火要求应比地面建筑更严格，墙面应采取不燃材料。
     五、事故照明、疏散指示标志与自备电源
   建筑火灾中，人员疏散与扑救的另一很大障碍是能见度差。为此，除平时正常照明，必须备有事故照明设备和自备电源，以便事故停电时能够照明，组织疏散和扑灭火灾。而且事故照明的照度一般不低于5勒克斯，同时要设置疏散标志灯，指明安全门和安全出口的方向；在人员密集的场所，应设置广播，通讯电话或对讲机。
     六、建筑必须采用合理的灭火设施
建筑灭火设施的设置，应该立足于“自救”，地下火灾的实际证明，由于高温、浓烟，消防人员还没有一个可靠有效的办法在地下建筑中进行灭火。近年来，我国地下建筑中先后发生了若干起火灾，也未能进行有效的扑救，都是因为烟大，温度太高，难以进入火场。因此，地下建筑中应该积极采用火灾自动报警器和自动喷水灭火系统。同时，要注意在人员较密集的场所严禁使用有毒的灭火剂，一般场所也尽量不使用有毒的灭火剂。
总之，建筑防火设计是贯彻“预防为主，防消结合”方针的重要体现，是遏制火灾事故，减少火灾危害的有效措施。建筑防火措施落实了，地下建筑的防火安全才能有保障。

Safety Design of Construction Discussion

Abstract: Fire design of underground construction of the relevant issues, summed up the design of underground construction in the fire service should be paid attention to several problems.
Key words: building fire safty, smoke partition incombustible safe evacuation of decoration material
Construction work should pay attention to fire prevention and fire early fire fighting, fire prevention based on the construction of internal facilities. Thus, the design of underground fire a lot of issues to be considered, such as general layout, building the fire resistance rating, fire district, fire distance, security, evacuation, fire fighting water supply, ventilation and air conditioning and electrical aspects of fire prevention. At the same time, also in accordance with the characteristics of the underground fire, fire control, control the spread of fire development, security, evacuation, automatic fire alarm and fire extinguishing equipment, such as a series of measures. Building Fire Safety Design in the ground, consideration should be given in the following main issues:
First, the use of underground construction and construction scale function
1, the total for the underground architectural design should be based on the city's overall planning, reasonable to determine its location, the fire interval, fire access and fire water.
2, A and B production and storage of goods should not be located in the underground building, which is China's current "architectural design code for fire protection" provided. In the "people's air defense fire safety engineering design," also provides that the "air defense works should not be set up within the high-pressure boiler room, ammonia refrigeration stations and A and B of the production workshop, warehouse goods." "Ban the use of civil air defense projects and liquefied petroleum gas flash point less than 60 degrees the liquid as fuel. "Generally speaking, A and B explosive materials after a fire burning very rapidly and is very intense, even violent explosions, underground after an explosion, fire fighting difficult. More seriously, a number of underground construction closed the incident, due to underground construction relief difficulties, shock wave will destroy the buildings, the consequences are extremely serious. Thus, to arouse sufficient attention.
3, staff-intensive public buildings should be located in the ground floor. Such as theaters, underground playgrounds, skating rinks, such as song and dance entertainment, it should only be set in the ground floor, indoor and outdoor floor surface height difference between the import and export should not be greater than 10 m; commercial and service sectors more underground movement of personnel Street to be located in the ground floor, and should be shallow. From China's specific situation, from the evacuation point of view of security, and personnel-intensive construction should be shallow. In addition, beyond the two-storey underground building, stairwell smoke should be fortified. In addition, the "people's air defense fire safety engineering design," also states: "The civil air defense projects should not be set up lactation rooms, kindergartens, nurseries and places of work disability. Office of shopping malls should not be set up business in the ground and three below the three-tier . "
Second, the underground construction of the fire, smoke Design Division
In order to ensure the event of fire, fire control can limit the scope for large-scale underground construction, as a result of staff-intensive, more combustible or fire risk of large, should be divided into a number of fire district, which is to prevent fires proliferation and the spread is very necessary.
Underground construction division of the fire district should be on the ground than the more stringent architectural requirements. According to "people's air defense fire safety engineering design" (2001 version) the latest revised edition, "the local store of a total construction area of more than 20,000 square meters, the firewall should be taken to separate them from other, and to open doors and windows firewall may not be the hole." But the 2006 version "architectural design code for fire protection" on the ground floor of a slight relaxation of the requirements of store: "Under the local store a total construction area of more than 20,000 square meters should be used to open doors and windows are not separated by the firewall hole. adjacent region local connectivity when needed, should be choose to adopt the following measures for fire-separated: First, submersion type square such as the use of outdoor open space; Second, the use of fire compartment; thirdly, to adopt the asylum corridor; Fourth, the use of smoke staircase, staircases, rooms with a door should be the use of Class A fire doors. "functions as the building, each fire district should not be greater than the general area of 500 square meters, but has a reliable fire prevention, fire fighting facilities, such as sprinkler systems, you can relax, but not great in 1000 square meters, underground civil air defense projects in the theater, the audience hall of the Office of the largest fire district should not allow the use of more than 1000 square meters area. At the same time, when the automatic fire-fighting equipment, its maximum allowable use of the area should not be increased. Commercial banking hall, exhibition hall, etc., when the set up of automatic fire alarm system and automatic fire extinguishing system, and the use of A-grade decoration and fitting-up materials, the fire district should not be greater than the maximum floor area of 2000 square meters. Entertainment should be fire resistance of not less than 2.00 hours and 1.00 hours of the walls of the floor and separated from other places, a hall, the building should not be larger than 200 square meters area. When the wall to open the door should be set not less than B fire doors. Ground Floor, Wall Street should be a firewall. The building area between the firewall should not be larger than 500 square meters.
Underground construction within the firewall, use the same concrete or brick building, with no less than three hours of fire resistance. Firewall to open the door, usually to the use of Class A fire doors, and two-way must be opened manually, with automatic opening and closing function. At the same time, there are limits to take fire shutter to fire separation, and to meet the requirements of its fire resistance.
Zoning should be designed to smoke combined with the design of fire protection district. In general, the smoke should not be across the fire district. A smoke partition should not be larger than the area of 500 square meters. The formation of smoke partitions, smoke generally wall, anti-cigarette curtain, fire doors, smoke machine.
Third, safe evacuation
The ground floor of buildings in the fire safety of the personnel is very important to the issue of evacuation.
1, the evacuation time is the safe evacuation of the basic indicators of the design. After the fire to make it in a short period of time through the evacuation of population from dangerous locations to evacuate to a safe place - outside or underground shelter. Therefore, the largest export to a safe distance, channel width, the number of exports, must be evacuated from the security needs time to determine. Japan believes that the fire department evacuated the underground construction time should be 3 minutes in between, if less than three minutes from the fire area evacuated to safe areas, staff is very dangerous. Relevant departments of China's underground cinema in a few experiments done on several occasions, officers from the staff to evacuate to the evacuation of the end of 3-4 minutes in general (some doors do not open), in which the import and export of most of the buildings to meet design width. For underground construction, because of the dangers of smoke, and in considering the safety of the evacuation, the evacuation time should be strictly controlled. References ground construction time and the evacuation of the evacuation of foreign underground construction time, construction of China's underground evacuation time should be controlled within 3 minutes.
2, on the speed of the evacuation, which is an important safety indicators evacuation. The problem of buildings of different functions, personnel composition of different lighting conditions are different, the difference is relatively large. Underground construction in the absence of natural lighting conditions, the rate will be smaller evacuation, especially of fire, as a result of normal power supply was cut off, the lighting in the accident rate of small cases, the evacuation of more than a small speed, therefore, values should be considered these negative factors.
3, underground construction must have sufficient width to evacuate. When the density of small staff, may be not less than two of the principle of direct exports to consider. Staff or more large-scale underground construction, safety of exports to the corresponding increase in the number, such as underground parking lot outside, there are generally safe for export 5-6; the peak number of 1,500 people at the underground station, located 2.4 meters wide export 6.
At the same time, should also be considered in the design of evacuation to a safe distance. Exit should not be set up according to different directions. Its distance from the room should meet the point farthest to the nearest distance from the exit should not be more than 15 meters; room door exit to the farthest distance from the maximum security, the general works should be 40 meters, the hotel is 30 meters, 24 meters hospitals. Street, in the ground within the evacuation should be considered by the unit to the outside stairs to evacuate from the best of not more than 20 meters; car park, garage, warehouses, substations and other units; export not more than 30 meters distance, but remain relatively part of many staff, not more than 20 meters.
For the construction of the underpass to connect the ground on both sides of the basement and the underground layout of business units, the width of the underpass could be 6 meters; unilateral arrangement of operating units, may be 5 m, of course, are very small in the neighborhood, fire danger is not , there is no obstacle to the evacuation of the conditions, may also have recourse to three meters. Design of underground when the accident conditions, taking into account the safety of emergency evacuation, not to the formation in a dead-end tunnel.
Fourth, underground construction and interior decoration of the non-combustible
Underground construction and interior decoration of non-combustible, and is related to the underground fire, evacuation and fire safety officers to fight the big problem according to "people's air defense fire safety engineering design," provided, "In addition to the Mass Transit Railway, highway tunnels and foreign theater, other fire resistance rating of the ground floor of a building, the entrance level of the ground fire-resistant construction should not be less than two. " Normal use of the underground works, the fire safety requirements should be more stringent than the ground construction, wall to be taken by non-combustible materials.
Five, accidents lighting, signage and self-evacuation of power
Tiefbau fire, evacuation and to fight another great