??????????????????
?й????е?????????
1.????????s??
???????????????????????????????????????????????????????????????????????????????Σ????????????????????????????????С?????????????
??Ps???????s??????????Fo?????????????????????s =Ps/Fo(MPa)??MPa???????????N??????/mm2????MPa=106Pa??Pa???????=N/m2??
???????????????????
???????GDP???????????????????2012??????GDP???????????130????????????GDP????????????????????????????????0.7????????????????????????0.5????GDP????1?????????????????0.5???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????7-8.5?????????????????????????????????????????????????????????
??????????????????
8??2000??8000 35??
8??2000??8000 42??
8??2000??8000 21??
8??2000??8000 32??
12??2000??8000 79??
??????????????7.0*1.5*6??q345qe???????????????????
