What Is a Basement Excavation?
Basement means that the height of the room floor below the outdoor ground level exceeds one-half of the clear height of the room. Multi-story and high-rise buildings require deep foundations. In order to take advantage of this height, constructing a basement under the building's ground floor can increase the use area and save the backfilling of the heart, which is relatively economical. Building a basement below the ground floor of a house can improve the efficiency of building land use. Some high-rise building bases are buried deep, making full use of this depth to build a basement, which has good economic and use effects. The basement is divided into ordinary basement and air defense basement according to function; according to structural materials, there are basement with brick wall and concrete structure, and there are full basement and semi-basement according to structural form.
- The ground plane of the room, the height below the outdoor ground plane exceeding the net height of the room is 1/2 as the basement. (Note: Quoted from GB / T50353-2013 "Code for Calculation of Construction Area of Construction Engineering")
- A basement is a room in a building below the outdoor floor. Building a basement below the ground floor of a house can improve the efficiency of building land use. Some high-rise building foundations are buried deep, making full use of this depth to build a basement has good economic and use effects.
- The type of basement is divided into functions, including ordinary basement and air defense basement. Divided by structural materials, there are basements with brick structure and concrete structure. According to the structure, there are full basement and semi-basement.
- The basement is generally composed of roof, floor, side walls, stairs, doors and windows,
- The outer wall and floor of the basement are deeply buried in the ground and are infiltrated by water and groundwater. Therefore, the problem of moisture and water resistance is an important issue to be solved in the design of the basement. Generally according to the standard and structure of the basement,
- Looking back on the situation of several modern high-tech wars in the 1990s, the protective effect of the air defense basement probably includes the following:
- I. The characteristics of modern war determine that general civil air defense engineering is not the direct target of enemy air strikes, at least not the main target
- Future wars will be partial wars under high-tech conditions. The main means of air strikes will be conventional weapon attacks under high-tech conditions. Nuclear weapons will serve as a deterrent for war. The basic method of air strike operations has shifted from large-scale saturated bombing to carefully selected political centers, heavy military groups, important infrastructures that have a strategic relationship with the overall situation of war, and key targets such as command, communication, and transportation hubs for precision strikes. .
- General civil air defense engineering is not the direct target of enemy air strikes. This is a major difference between civil air defense engineering and other defense engineering such as the launching of important weapons, various battlefield engineering and command engineering. This understanding has long been accepted by the people under the conditions of nuclear air strikes, and no one believes that civil air defense engineering is the main target of nuclear strikes. The built air defense basement is an important part of civil air defense engineering, and it has a large amount and a wide range, and is scattered. Most of it is located in urban residential areas. It is not the main target of enemy air strikes. The role of civil air defense engineering is to protect urban residents Collateral damage from air strikes.
- Civil Air Defense Basement
- 2. Under the conditions of modern air strikes, the civil air defense engineering system constructed in accordance with the current protection standards has a better overall protection effectiveness.
- The current protection standards for civil air defense engineering stipulated in the "Tactical and Technical Requirements for Civil Air Defense Engineering" are basic indicators based on the classification of resistance to ground-based overpressure of nuclear weapon shock waves, and they also have protection requirements for conventional weapons air strikes. Of course, civil air defense projects (including "building" air defense basements) do not require resistance to direct hits of the bombs, but require technical measures to limit the threat of damage from direct hits by the bombs. As long as the layout is reasonable (a certain distance from important targets), the probability of being directly hit is extremely low. Therefore, it has a considerable degree of security. For the large-scale and wide-ranging air defense basement project, considering the direct hit of anti-aircraft bombs and improving the protection ability of the project, not only our economic power cannot bear it, but also the improvement of the survivability of the sheltered personnel is very small. Therefore, the division of protection units and anti-explosion units in civil air defense engineering can reduce the scope of damage, which can greatly reduce the hazards of war, and can effectively improve the survival probability of personnel in the "built" air defense basement.
- Broadly speaking, all underground buildings have varying degrees of resistance to conventional weapon explosions, and the construction of air defense basements is no exception. Under indirect hit conditions, even the air defense basement project with the lowest resistance level can effectively resist the impact of bomb shock waves and shell fragments, and can withstand the loads generated by scattered building material fragments, ensuring the safety of personnel located in the air defense basement.
- The underground air defense basement has good explosion-proof and fire-proof functions. In general, there are corresponding protective measures against secondary disasters on the ground after an air strike, including city fires, chemical explosions, ground building collapse, air pollution, the spread of toxic and hazardous substances, water cuts, and power cuts. The isolation ventilation and poison filtering ventilation system of the air defense basement can prevent the toxic, harmful nuclear, chemical, and biomass generated by the air strike from entering the civil air defense engineering, thereby ensuring the safety of the personnel in the project.
- 3. Raise awareness and build air defense basements in accordance with law to ensure project quality
- Conducive to China's economic construction. But hegemonism and power politics still exist, political frictions in some areas, armed conflicts continue, and the world is not peaceful. Unstable factors still exist in the surrounding areas of China. We must remain vigilant, firmly establish the concept of war, strengthen national defense and civil air defense, and make all preparations for coping with war. Strengthening the construction of civil air defense projects in accordance with the law will not only have important strategic significance for improving the city's air defense capabilities, preserving war potential, and protecting people's lives and property, but it will also have a certain deterrent effect on maintaining world peace and delaying and restricting the outbreak of war. The civil air defense project has a long construction period, and it is too late to rely on combat assaults. It must be synchronized with the unified planning of national capital construction and urban construction. The construction unit must consciously fulfill the obligations set by the civil air defense laws, regulations, and rules, and simultaneously build the air defense basement while developing and constructing civil buildings; the design unit must design in strict accordance with the current tactical and technical requirements of the standard; We must conscientiously check the drawings, check the quality control, and complete the acceptance check to ensure the quality of the built air defense basement, so that it can effectively protect people's lives and property in modern warfare, and ensure the smooth construction of socialist modernization. get on.