Housing is urban and rural construction ministry about issueing national standard " design of building construction dependability unites a standard " announcement
Approve now " design of building construction dependability unites a standard " for national level, number is GB50068-2018, carry out since April 1, 2019. Among them, the 3.2.1st, 3.3.2 are mandatory article, must carry out strictly. Former " design of building construction reliability unites a standard " (GB50068-2001) abolish at the same time.
This standard is in housing is urban and rural website of construction department family status (Www.mohurd.gov.cn) open, and by housing China of organization of institute of norm of ministerial standard of urban and rural construction builds industrial press to publish.
Housing of People's Republic of China and ministry of urban and rural construction
On November 1, 2018
This standard castigatory is main technical content is:
1. and " design of engineering construction dependability unites a standard " GB50153-2008 undertook be harmonied in the round;
2. adjusted the setting level that building construction safety spends, the extraction that raised relevant action to divide a coefficient is worth, right the basic combination of action, cancelled original standard to remove the combined-type that controls function when Yong Zehe carries effect to give priority to;
3. increased an earthquake to design a condition, aseismatic to building a structure design, bring seized " small shake is not bad, medium shake can be repaired, big shock does not fall " design concept;
4. perfects the regulation that has structural dependability assess already;
5. increased the relevant provision that firm sex designs structural whole newly;
6. added the relevant provision that position of structural wear maximum designs newly to wait.
The article that indicates with bold-face in this standard is mandatory article, must carry out strictly.
Released 2018, carried out on April 1, 2019 " design of engineering construction dependability unites a standard " GB50153-2008, among them the most seductive change is:
Constant load divides a coefficient by 1.2 adjust 1.3!
Live load divides a coefficient by 1.4 adjust 1.5!
γ G: Of permanent action divide a coefficient (constant load) ;
γ Q: Of alterable action divide a coefficient (live load) ;
γ P: Of prestressing force action divide a coefficient.
Via structural major the personage calculates: Content of average house reinforcing steel bar will increase 5% ; Content of subterranean garage reinforcing steel bar will increase 10% .
One, what is constant load and live load?
Floor constant load includes a construction self-prossessed wait with top of outfit shave layer, condole, decide by practice of building, structure. The load that floor live load includes personnel, equipment, furniture to wait, by the building the function is used affirmatory. That is to say constant load produces by building itself, live load produces by the person that use.
2, what is load divides a coefficient?
Load divides a coefficient is to be in design computation, the uncertainty that reflected load and related to structural reliability concept a numerical value of couplet. Load divides a coefficient is to show ultimate position is designed, to satisfy the requirement of reliability, lever of the computation in be being designed actually when internal force, multiply to load mark fiducial value in order to be more than the coefficient of 1.
3, analyse to the influence of steel dosage and cost?
Average house part:
Content of reinforcing steel bar will increase 3-5% , content of residential part reinforcing steel bar is 50 kilograms about so / ㎡, will turn into 50*1.05=52.5 kilogram / ㎡, reinforcing steel bar presses 5000 yuan / ton plan (contain artificial cost) , cost of every square metre will raise average house 2.5*5=12.5 yuan.
More startling is subterranean garage:
Content of reinforcing steel bar will increase 10% , content of subterranean garage reinforcing steel bar is 120 kilograms about so / ㎡, will turn into 120*1.1=132 kilogram / ㎡, reinforcing steel bar presses 5000 yuan / ton plan (contain artificial cost) , cost of every square metre will raise next garages 12*5=60 yuan.
Subterranean garage occupies the 1/4 of whole village floor area, the cost influence of meeting project is so tremendous. Of course concrete dosage also can increase somewhat, affect to integral cost nevertheless not quite.
