Foundation and slab questions
第5区的所有者/ Builder SFR新建建筑物（6200'高于Reno）。在17％的南方面向斜坡上，稍微易碎的基岩从地面下方的1'到4'变化。1000平方英尺。车库平板级坡/脚踏板/ Stemwall基础。1200平方英尺的两个故事房子，带有梯级脚/斯蒂瓦尔爬行空间基础。
The building inspector has already given the ok to drill into the bedrock and connect the stemwall directly to the rock where it can’t be dug with the backhoe.
The footing is 16″ wide, 7.5″ tall, with 16″x16″ steps about every 10′ or so to go down the slope. The stemwalls are 7.5″ wide and vary from 16″ to 48″ tall, the max height to avoid engineering.
这款基础底座系统可以倒单片吗？带有开放式顶部的基础形式？正在思考它可以用第一浇注/升降填充所有脚踏台的升降机，然后是脚，然后是两个或三个升降机的螺杆。我已经看到承包商一次倾吐脚踏板/ Stemwalls，但没有与台阶的斜坡。似乎是一种很好的选择，避免在地震/高风区域中的寒冷脚到挡板接头。将有一个混凝土泵车来做这件事。
It’s just kind of scary to try and get the slump correct. Helping my neighbor pour his slab in two parts on two different days and two different slumps made the work dramatically different.
On the slab want to put 1-1/2 of EPS underneath and then a 12″ square grid of #4 rebar. Want to be able to drive a 6500 lbs Bobcat on it and bring in some heavy machinery (10,000 lbs?) with a forklift. Was thinking of going to a 5″ thickness? The 12″ square seems good for the pour, so you can step in the holes while working it, compared to the 8″ woven mesh. Could this dimension go to 16″ square?
My neighbor completely eliminated the rebar in his slab just going with the small fiber reinforcing, but I thought this was only to control drying cracks?
Should I go with the budget Home Depot EPS? That does say it’s rated for under-slab. Or something with a higher PSI rating?
There is also some fill under the slab, up to three feet in depth. Should this be building sand, or should it be road base?
The only other thing that seems problematic is how do you set up a screed edge on the slab when the footing/stemwall is already poured? The stemwall will be up to 4″ higher than the slab, and slab is sloped to drain toward the garage doors. You could do the slab in two parts which would give you a center edge. But the edge at the wall is the issue. The only DIY info I’ve found is to hand trowel an edge during the first part of the pour. Seems like one of those things that’s going to be difficult on a first time, one time basis.
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答复
嗨克里斯 -
pretty complicated project and post. It sure sounds as though you need local expertise; you are not the first landowner in your neck of the woods who has had to figure out--or pay a professional to figure out--your approach.
我可以告诉你的一件事：通过类型查看EPS的抗压强度的EPS行业联盟技术信息：http://epsindustry.org/building-construction/compressive-strength.
Peter
克里斯，
We pour most of our foundations monolithically. That's made easier because most builders here form with boards, and use a 2"x4" on the top of the footings which helps contain the concrete. Much like this:https://www.alibaba.com/product-detail/concrete-plywood -forming-strip-tie-snap_60009926741.html.
The upsides as you say, are increased strength, and a savings in time, labour and pump fees. The downsides are a capillary break isn't possible, and the forms can move a bit vertically if not well-staked.
The one situation that sometimes makes builders here do two pours are steps in the footings. Depending on how deep and how many, it is sometimes easier to pour them separately. Yours sound pretty simple. I'd be tempted to p0ur all at once, but if it's your first time, you might want to err on the side of caution. You can easily make up for any loss of strength by making the footing an wall rebar continuous.
对于我被告知的地板使用可调节的高椅来设置一条圆形管道，因此管道的顶表面甚至是成品的地板。
use the pipe to screed, then slide it towards you, filing in the groove as you trowel or float the floor.
RE：板坯设计：我参与了许多具有沉重负荷的工业项目。其中许多人没有在板坯中加强钢材，但它们并没有过度保温，并且它们都有一定程度的控制接头和设计，以在控制接头处转移载荷。不同的填充量。我不是工程师。您需要带入可以压实的分级砾石或石头（与公路基地相同），并在8“升降机中安装，压缩每个升力，关注含水量。您需要一个体面的机器压实。绝缘可能需要是为广场甲板制造的高psi xps等。我的猜测是你需要至少6英寸的板块，也许更多。您需要使用SawCuts或其他方式计划裂缝控制，然后计划在关节上传递负载。100,000磅的机器可以在完全装载时将其大部分重量放在前轮上。也许与工程师的讨论是有序的。