几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量  


返回   几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量 » 三维空间:产品设计或CAX软件使用 » CAD设计 » 产品功能分析
用户名
密码
注册 帮助 会员 日历 银行 搜索 今日新帖 标记论坛为已读


回复
 
主题工具 搜索本主题 显示模式
旧 2009-09-08, 09:29 AM   #1
huangyhg
超级版主
 
huangyhg的头像
 
注册日期: 04-03
帖子: 18592
精华: 36
现金: 249466 标准币
资产: 1080358888 标准币
huangyhg 向着好的方向发展
默认 cmu block walls with hollow core slab - how high

cmu block walls with hollow core slab - how high???
just curious - how many stories tall have you built using cmu block load bearing walls with a hollow core slab system? we are looking at an 8 story hotel and wondering if this type of construction is feasible for such heights.
find a job or post a job opening
i've never done it, but my "reinforced masonry engineering handbook," fifth edition, by amrhein has an example of a seven story building.
do a calculation using maximum reinforcement, all cores filled and site wind load at ground level.
then calculate the maximum allowable axial capacity concurrent with the wind load.
divide this by 1.5 to allow for doors/windows e.t.c. and then figure out how many stories that will support.
this will give you a preliminary design.
rules of thumb only get you so far.
csd
this sounds feasible but will be affected by the architectural concept, the framing scheme and the amount of lateral load determined by basic wind speed, exposure, and seismic parameters.
can all of the bearing walls be carried to the ground? are all floor to floor heights the same?
normally, the precast spans the long way of the hotel over two rooms, about 28 feet. intermediate walls between rooms are non-load bearing stud walls. this can provide for doors between pairs of rooms.
do some prelim. calculations as csd72 suggests to determine structural feasibility.
you might also look at using precast with steel framing. will your masonry be affected by winter construction?
also check out the ibc (or asce 7) if you are in seismic areas as table 1617.6 has height limits for bearing wall systems.
another idea is to look at hollowcore with precast bearing walls.
in a similar scenario, i have discovered cold formed steel studs to be a much more cost effective alternative to the block and plank system. the cold formed sigmastud easily builds eight stories and works well with a hollow core plank floor system. the foundations are able to be reduced by the reduced weight, and base shear is much less. shear forces are resolved using a flat strap shear wall system.
not hollow core, but - the highest i have seen was about 20 stories of 6" (140 mm) block. the project consisted of a number of building ranging from 15 to 20 stories. the building was in brasil. since quality high strength 6" block were available, there was no justification to go to 8" walls.
they used four or five different strengths of block depending on the floor level. the walls were partially reinforced with very little extra vertical reinforcement on the upper floors beyond the normal reinforcement for doors and windows. the masonry walls were generally designed in accordance with aci 530 or the predecessor design standard (ncma "green book").
the floors in brasil were two-way cast in place slabs and were about 5" thick if i recall correctly.
it was a typical loadbearing apartment building with both exterial and most interior walls loadbearing. room sizes were in the range of 9x12 to 10x20.
there was a large amount of engineering that went into creating the excellant drawings and details. there was also a great deal of coordination between designers, suppliers and contractors in comparison u.s. projects. the amount of engineering involvement and attention to details was very impressive. because of the quality control and inspection practices implemented, very few prisms were cast on the site and all units were identified and pre-qualified at the plant because 5 to 10 buildings were undergoing construction at the same time using different strength units.
there are numerous 8 to 12 story loadbearing buildings in california and the excalibur in las vegas is 28 stories. most of the were constructed using 8" block and lift slabs and 4000 f'm block. the lift slabs were generally chosen because of speed of contruction and scheduling crane time.
the maximum height of you building with hollow core plank will depend on the efficiency of the bearing/shear wall layout and the spans. with a reasonable building shape and wall layout, spanning two hotel rooms with a single hollow core is very reasonable on an 8 story building.
which ever type of floor system you use, find out from the local supplier what maximum block prism strengths (f'm) are available. the excalibur was 4000 psi and the company i was with offered a 4500 psi f'm unit in our product line, but could have gone a little higher.
dick
__________________
借用达朗贝尔的名言:前进吧,你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]
huangyhg离线中   回复时引用此帖
GDT自动化论坛(仅游客可见)
回复


主题工具 搜索本主题
搜索本主题:

高级搜索
显示模式

发帖规则
不可以发表新主题
不可以回复主题
不可以上传附件
不可以编辑您的帖子

vB 代码开启
[IMG]代码开启
HTML代码关闭

相似的主题
主题 主题发起者 论坛 回复 最后发表
【转帖】set Block Attribute Values yang686526 DirectDWG 0 2009-05-07 03:36 PM
【转帖】memory leak issue yang686526 DirectDWG 0 2009-05-06 05:37 PM
【转帖】grouping in svg based on block hierarchy yang686526 DirectDWG 0 2009-05-05 11:41 AM
【转帖】cloning a block yang686526 DirectDWG 0 2009-05-04 05:50 PM
【转帖】a dimension error yang686526 DirectDWG 0 2009-05-04 03:05 PM


所有的时间均为北京时间。 现在的时间是 10:21 PM.


于2004年创办,几何尺寸与公差论坛"致力于产品几何量公差标准GD&T | GPS研究/CAD设计/CAM加工/CMM测量"。免责声明:论坛严禁发布色情反动言论及有关违反国家法律法规内容!情节严重者提供其IP,并配合相关部门进行严厉查处,若內容有涉及侵权,请立即联系我们QQ:44671734。注:此论坛须管理员验证方可发帖。
沪ICP备06057009号-2
更多