T**9
发帖数: 1528 | 1 今天被问到这个问题，一时不是很肯定。
我的理解 live load reduction 是用在单个 structural member 的设计,
如果设计比如 整个mat foundation, no live load reduction |
C*S
发帖数: 1658 | 2 what? isn't it the other way? |
Z****g
发帖数: 13731 | 3 There is live load reduction for foundation. Live Load Element Factor Kll=1.
0, foundation is also considered an element.
【在 T**9 的大作中提到】
: 今天被问到这个问题，一时不是很肯定。
: 我的理解 live load reduction 是用在单个 structural member 的设计,
: 如果设计比如 整个mat foundation, no live load reduction
|
T**9
发帖数: 1528 | 4 比如说，要sizing a mat foundation supporting the columns of a 5 story
building
Assume L0=50 psf.
The area of mat slab of course is 40,000ft^2 way over 400 ft^2.
Tributary areas of most columns 900 ft^2 are also greater than 400 ft^2.
How would you implement live load reduction to get the load on the
foundation?
Let's say using service load combinations:
D+L
D+0.75L+0.7E+0.75Lr
Thank you.
1.
【在 Z****g 的大作中提到】
: There is live load reduction for foundation. Live Load Element Factor Kll=1.
: 0, foundation is also considered an element.
|
Z****g
发帖数: 13731 | 5 use the tributary area for the mat (40,000 sq.ft.) and the formula in ASCE
or
IBC with Kll=1.0, to calculate the reaction from the oil. Accordingly, the
force from column will use this reduction factor too (not the factor with
400 sq.ft).
This is my interpretation.
【在 T**9 的大作中提到】
: 比如说，要sizing a mat foundation supporting the columns of a 5 story
: building
: Assume L0=50 psf.
: The area of mat slab of course is 40,000ft^2 way over 400 ft^2.
: Tributary areas of most columns 900 ft^2 are also greater than 400 ft^2.
: How would you implement live load reduction to get the load on the
: foundation?
: Let's say using service load combinations:
: D+L
: D+0.75L+0.7E+0.75Lr
|
z******i
发帖数: 5114 | 6 规范里有有提到的，两层以上的，还是怎么的，live load可以折减，有一定条件的，
不是所有的都可以，具体的记的不是很清楚，不过，确实有live load折减这么一说
问这里，还不如去看规范，直接，省时间 |
Z****g
发帖数: 13731 | 7 he did read the code, he just have questions about the code.
【在 z******i 的大作中提到】
: 规范里有有提到的，两层以上的，还是怎么的，live load可以折减，有一定条件的，
: 不是所有的都可以，具体的记的不是很清楚，不过，确实有live load折减这么一说
: 问这里，还不如去看规范，直接，省时间
|
C*S
发帖数: 1658 | 8 The rational is: 构件所支撑的总楼层面积越大，那么这些面积上同时满布活载的概
率就越小， 故而做适度折减。(当然有例外，比如图书馆的书籍荷载，舞厅的蹦嚓嚓荷
载等)。 |
