课程名称︰钢筋混凝土学
课程性质︰土木工程学系必修
课程教师︰欧昱辰
开课学院：工学院
开课系所︰土木工程学系
考试日期（年月日）︰2018/9/27~2018/10/4
考试时限（分钟）：壹万零捌十分钟
试题 :
作业二(Homework two)
缴交日期(Due date):10/4
(1)扼要回答以下问题：
(a)为何载重组合U=0.9D+1.0E+1.6H中，静载D载重因子小于1，而非大于1（载重不放大
反而缩小）？
(b)为何载重组合U=0.9D+1.0E+1.6H中，地震力E之载重因子等于1，而非大于1（载重不
放大）？
Answer the following questions concisely:
(a) Why is the load factor of dead load (D) less than 1.0 rather than equal
to or larger than 1.0 (the load is reduced rather than magnified) in the
load combination U=0.9D+1.0E+1.6H?
(b)Why is the load factor of earthquake load (E) equal to 1.0 rather than
larger than 1.0 (the load is not magnified) in the load combination U=0.9D+
1.0E+1.6H?
(2)一矩形梁宽40cm，有效深度60cm，拉力筋为6支D29 (Ab = 6.47cm^2)，混凝土强度fc'
= 280kgf/cm^2，钢筋降伏强度fy=4200kgf/cm^2，求φMn。
注：
(a)本题合并自97与102年高考题。
(b)假设极限状态拉力筋降伏，但须检核是否降伏。
A rectangular beam has a width of 40cm and an effective depth of 60 cm. It
has 6 D29(Ab = 6.47cm^2) longitudinal tension reinforcement. The compressive
strength of concrete fc' = 280kgf/cm^2. The yield strength of reinforcement
fy = 4200kgf/cm^2. Calculate φMn.
Note:
(a)This question is from a past national exam.
(b)Assume tension reinforcement yields at the ultimate condition. Need to
verify this assumption.
(3)于建筑物评估时，已知一梁，b = 30cm，d = 50cm，As = 6 根 D25 = 30.4cm^2，
fc' = 140 kgf/cm^2，fy = 4200 kgf/cm^2，求φMn。
注：
(a)本题为103年结构技师考题。
(b)假设极限状态拉力筋未降伏，但须检核是否未降伏。
In the performence evaluation of a building, a beam is found to have b = 30
cm, d = 50 cm, As = 6 D25 bars = 30.4cm^2, fc' = 140 kgf/cm^2, and fy = 4200
kgf/cm^2. Calculate φMn.
Note:
(a)This question is from a past national exam.
(b)Assume tension reinforcement does not yield at te ultimate condotion.
Need to verify this assumption.