Blog Archives

SIZING TALL STACKS

Posted by on 14/ 11/ 15

Sizing tall stacks will require you to use different sizing tables. A tall stack is one that has more than three branch intervals. Figure 4.19 and Figure 4.20 will show you the basics needed to size tall stacks for two different codes. There are differences in the number of fixture units allowed between the two codes. Since the tables are so much like others we have used, I won’t go into a lot of detail on them.

SUPPORTS

SIZING TALL STACKS

supports for drainage systems are needed. The distance between supports varies with the type of pipe being used and the local code that you are work­ing with. There are also differences between vertical and horizontal piping when you are designing your support placement...

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The Good, the Bad and the Sprawling

Posted by on 14/ 11/ 15

Over-consumption is reflected not only in the scale of our houses, but in the sizes of our yards and streets as well. Oversized lots on vast roads, miles from any worthwhile destination, have made the American suburb as inhos­pitable as it is vapid.

Like the design of our houses, the form of our neighborhoods is mandated by a long list of governmentally-imposed regulations that reflect our national taste for the enormous. In most U. S. cities it is currently illegal to build places like the older ones pictured in this book. Taos Pueblo, Elfreth’s Alley, and Rue de Petit-Champlain all violate current U. S. zoning ordinances. Narrow, tree-lined streets with little shops and houses sitting at the sidewalk’s edge are against the law...

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COMPOSITE PAVEMENT (OVERLAYS)

Posted by on 14/ 11/ 15

Rigid pavement constructed with an asphalt overlay is referred to as composite pavement. The advantage of constructing an asphalt overlay on a rigid pavement is solely in the areas of ridability and noise. Rigid pavements are considered by most to create more road noise inside a vehicle than flexible pavements. This phenomenon is largely due to the surface texture specified for rigid pavements to ensure proper skid resistance. By specifying an asphalt overlay with the rigid base, surface texture requirements can be relaxed and noise can be reduced.

There are few documented composite pavement design procedures available to determine the proper thickness ratios between the rigid base thickness and the flexible surface thickness...

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The pharaoh and the lake: the great hydraulic works of the IInd millennium BC

Posted by on 14/ 11/ 15

In prehistory the Joseph canal, or Bahr Youssouf, supplied water to Fayoum through an ancient arm of the Nile. At that time Fayoum comprised an immense body of water and marshes, with a water surface elevation somewhat below that of the Nile. Little by lit­tle, sedimentation raises the elevation of the plain. In about 7500 BC, hydraulic con­

nection of the region to the Nile is not continuous but episodic, causing periods of rising and falling lake levels. Throughout the IIIrd millennium BC, the lake level appears to have remained low, at an elevation that is thought by some to be around -2 m,[106] the level of the Nile being around +20 m at this time. At this time the large lake was natu­ral, occupying roughly the area within the contour 0 on Figure 3.6...

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FLEXIBLE PAVEMENT

Posted by on 14/ 11/ 15

Asphalt concrete pavement, also referred to as flexible pavement, is a mixture of sand, aggregate, a filler material, and asphalt cement combined in a controlled process, placed, and compacted. The filler material can range from quarry crushing dust and asphalt-plant baghouse fines to wood fibers (cellulose). There are many additives that can be used in asphalt concrete mixes to encourage thicker cement coatings, more elastic mixes, stiffer mixes, and less temperature-sensitive mixes...

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The “marvelous” lake of Moeris. Fifteen centuries of work to devel­op Fayoum

Posted by on 14/ 11/ 15

The Fayoum Depression, located 80 km southwest of Memphis (see Figure 3.1) in the “lake province” of the ancient Egyptians, was prized by the pharaohs and viewed as a marvel by Greco-Roman travelers. Strabo wrote:

“(This region) contains also this admirable lake that is called the Lake of Moeris and has the

dimensions and color of a sea.”[104] [105]

This region has a long history. It was first developed at the beginning of the IInd millennium BC by the pharaohs of the XIIth Dynasty. It was visited by Herodotus in 460 BC, and redeveloped by the Ptolemite successors of Alexander in the 3rd century BC. Strabo visits the region in 25 BC, at the dawn of the Roman domination during which Fayoum was one of the granaries...

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Radiation

Posted by on 14/ 11/ 15

Radiation is a process by which energy moves through a medium or vacuum without the movement of any molecules and without heating any medium through which it passes. The quantity of energy radiated from a grain surface increases with increased surface temperature and neighbouring grains increase their temperature by absorb­ing the radiation emitted. Because the higher-temperature grains radiate more en­ergy, radiation results in a net transfer of energy to the lower-temperature grains. For coarse dry soils heat conduction is low and 10-20% of heat transfer can be due to radiation. Generally though, radiation plays a negligible role for heat transfer in soils.

4.2.2 Vapour Diffusion

Vapour moves towards a lower vapour pressure by a molecular process known as diffusion (fundamentally the s...

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Mark exterior walls first

Posted by on 14/ 11/ 15

If the deck perimeter isn’t parallel and square, the walls won’t be either. Take the time to check this now, following the procedure explained in chapter 3 (see pp. 54-56). If nec­essary, lino-tune the exterior wall layout to correct for out-of-square corners or nonparal­lel walls. The lines you snap define the inside
edge of the exterior walls. For 2×4 walls, mea­sure ЗV: in. in from the deck edge (slightly more or less if you need to get the walls square and parallel). If the walls will be framed with 2x6s, use a 5’/-in. measurement. Instead of measuring this distance, you can simply lava scrap 2×4 (or 2×6) on the deck and mark against its inside edge...

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Continuously Reinforced Rigid Pavement

Posted by on 14/ 11/ 15

As the name implies, continuously reinforced concrete (CRC) pavement is a rigid pave­ment constructed with continuous longitudinal reinforcement. No transverse joints are installed. Instead, the pavement is allowed to develop random transverse cracks, and the steel reinforcement holds the cracked sections together. The size and spacing of the cracks are influenced by the percentage of reinforcing steel used. Current practice calls for 0.6 to 0.7 percent of the slab cross-section area. The design of the reinforce­ment is covered in the AASHTO Pavement Design Guide. The thickness of the slab is determined the same way as for other concrete pavements.

Continuously Reinforced Rigid Pavement

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FIGURE 3.7 Typical preformed joint seal in rigid pavement. Conversion: 1 in = 25.4 mm.

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A HORIZONTAL BRANCH

Posted by on 14/ 11/ 15
Подпись: *Table does not represent branches of the building drain, and other restrictions apply under battery-venting conditions. tNot more than two toilets may be connected to a single З-in horizontal branch. Any branch connecting with a toilet must have a minimum diameter of 3 in.

Let’s talk about how you can size a horizontal branch. Bet you can guess that we are going to use a sizing table. Hey, they’re easy, fast, and accu­rate, so why not use them? Look at Figure 4.16. This table shows you the maximum number of fixture units that may be placed on a single horizon­tal branch of a given size. If you look closely, you will see, once again, that not more than two toilets can be installed on a single 3-inch pipe that is in­stalled horizontally. It should also be noted that the table does not repre­sent the branches of a building drain and that other restrictions may apply if doing a series of battery venting.

Pipe size (in)

Maximum no. of fixture units

1 Vi

1

V/2

2

2

6

3

20t

4

160

6

620
A HORIZONTAL BRANCH

FIGURE 4...

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