tailieunhanh - Nguyên tắc thi công công trình

Tài liệu tham khảo dành cho giáo viên, sinh viên, kiến trúc sư chuyên ngành xây dựng - Giáo trình kiến trúc xây dựng, bao gồm đầy đủ các vấn đề liên quan đến chất lượng và thi công công trình. | UNITS AND SYMBOLS basic unit unit symbol definition based on SI units in the definition 1 length metre m wavelength of krypton radiation 2 mass kilogram kg international prototype 3 time second s duration period of caesium radiation 4 electrical current ampere A electrodynamic power between two conductors kg m s 5 temperature kelvin K triple point of water 6 luminous intensity candela cd radiation from freezing platinum kg s 7 quantity of matter mole mol number of carbon atoms kg SI basic units The statutory introduction of SI Units took place in stages between 1974 and 1977. As from 1 January 1978 the International Measurement System became valid using SI Units SI Système Internationale d Unites . prefixes and t heir abbreviations are T tera 1012 billion c centi 1 100 hundredth G giga 109 US billion m milli 10 3 thousandth M mega 106 million M micro 10-6 millionth k kilo 103 thousand n nano 10 9 US billionth h hecto 100 p pico 10 12 billionth da deca 10 f femto 10 15 US trillionth d deci 1 10 tenth a atto 10 18 trillionth no more than one prefix can be used at the same time 2 J Decimal multipliers area 1 m X 1 m 1 m2 velocity 1 m X 1 s 1 1 I ms 1 1 m s acceleration 1 m X 1 s 2 1 ms 2 1 m s2 force 1 kg X 1 m X 1 s2 1kgms2 1kg m s2 density 1 kg X 1 m 3 1 kg m 3 1 kg m3 Examples of deriving SI units quantity unit symbol dimensions M mass L length T time relationships area A m2 L2 - volume 1 m3 L3 - density p kgm 3 ML 3 - velocity V ms 1 LT 1 - acceleration a ms 2 LT 2 - momentum p kgms 1 MLT 1 - moment of inertia l J kgm2 ML2 - angular momentum L kgm2s 1 ML2T 1 - force F newton N MLT 2 1 N 1 kgm s2 energy work E w joule J ML2T 2 1 J 1 Nm 1 Ws 1 kcal 4186 J 1 kWh MJ power p watt W ML 2T 3 1 w 1 J s pressure stress p Ơ pascal Pa ML ư 2 1 Pa 1 N m2 1 bar 105 Pa surface tension Y Nm 1 ML IT-2 - viscosity 7 kgm s 1 ML 1T 1 - symbol name unit meaning and relationships ampere A current V volt V potential difference 1 V 1 W A R ohm 2 resistance 1 2 1 V A Q coulomb C .