Blog Archives

Summary of the Method

Posted by on 16/ 11/ 15

The determination of air voids based on compacted Marshall samples has been regarded in the Netherlands as the weakest point of the Dutch method of design. According to many engineers, these samples do not reflect the true arrangement of coarse aggregate particles in real pavement. Under real-world conditions, displacement of grains and their close arrangement occur as a result of the high temperature of the pavement and post-compaction; this may be followed by the reduction of air voids among the par­ticles that create the skeleton. Then a significant decrease of air voids in the pavement can result, right up to a complete filling-up with mastic...

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About the drawings

Posted by on 16/ 11/ 15

Construction terms vary regionally, and the names for the components that frame wall openings (see 68A) are the least cast in stone. Studs called “trimmer studs” in one locality are called “jack studs” in another; and the bottom plate may go by either “bottom plate” or “sole plate.” Consult local builders and architects for common usage.

For clarity, insulation is not generally shown in the exterior walls except in the insulation section (120-125).

OPENINGS

 

RAKE WALLS SEE 72

 

CONNECTIONS WITH ROOF & CEILING SEE 132-134

 

LATERAL

bracing SEE 77

 

corners SEE 70A & D, 71

 

SEE 73A & В

 

SEE 73c & D

 

About the drawings

resource-efficient advanced framing

SEE 74 NOTE

IN THIS cHAPTER ALL 2×4 wALLS ARE SHOwN with stud...

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The hydraulic works of Samos: record achievements in the Greek world

Posted by on 16/ 11/ 15

The city of Samos in Ionia is located near the coast of Asia Minor on an island of the same name. A spectacular tunnel more than 1,000 m long was dug for its water supply (Figure 4.15). The tunnel was bored in two sections starting from its extremities (the meeting point of the two bores is shown by an arrow on Figure 4.15). The water supply conduit was laid at the bottom of a trench dug into the floor of the tunnel. Because of this trench, it was possible to dig a horizontal tunnel (a relatively straightforward task); the depth of the trench is zero at the entrance to the tunnel and progressively increases to reach nearly 8.5 m at the tunnel’s exist, assuring the slope necessary to convey the flow.

The hydraulic works of Samos: record achievements in the Greek world

Figure 4.15. Plan view of the aqueduct of Samos and the tunnel of Eupalinos.

Hero...

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Step 8-Set Jack Rafters

Posted by on 16/ 11/ 15

Set first jack rafter on 16” or 24" spacing with common rafters.

Measure length from common rafter to first jack rafter and then use standard jack rafter differences, as given in framing square table, to measure lengths of remaining jack rafters along the hip rafter.

12

For 17 pitch

Framing Square Segment

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ШГТІтїї

JFTFjJ

рттлт

ф|||||ф|ф

TTW

8

|ЇЇЧПТ

ПфП|і

"ІИІ

LENGTH COMMON RAFTERS PER FOOT RUN

21

63

20

81

20

11

HIP OR VALLEY » »

и

24

74

Cs]

CM

О

23

32

DIFF

IN LENGTH OF JACKS 16 INCHES CENTERS

28

%

26 и/le
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Water supply for Greek cities

Posted by on 16/ 11/ 15

Greek cities develop their water supply using local springs and aqueducts of terra-cotta conduits, following the centuries-old Cretan and Mycenaen traditions. These conduits are set underground, both for their protection and to accommodate irregular topography.

They are assembled from interlocking pre-fabricated elements from 60 cm to 1 m long, and between 11 and 22 cm in diameter.[156] Some of the individual elements have a hole in their crown, normally plugged with clay, very likely intended to provide access for inspection and cleaning of the pipes. The presence of these inspection holes, as well as the thinness of the walls (2 to 4 cm), clearly suggest that these pipes conveyed water through free-surface gravity flow, not under pressure.

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Commonly used bolts

Posted by on 16/ 11/ 15

Carriage bolt

Commonly used bolts

 

m

 

Commonly used bolts

Stove bolt

 

ішшшиишщшшш

 

ШШШк

 

m

 

Commonly used bolts

Lag bolt

 

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Commonly used bolts

Commonly used boltsCommonly used boltsCommonly used boltsCommonly used boltsCommonly used bolts

Commonly used bolts

Drywall screws love plywood—they zip through а 3/нп.-thick sheet in nothing flat—so they’re great for attaching sheathing or flooring. But drywall screws are somewhat brittle, so don’t use them in shear walls (which are built to resist the shear forces of earthquakes and high winds) without first getting approval from an engineer or your build­ing department. Drywall screws can also break when being driven into thick stock or hardwoods. I have driven a 3-in. screw through 2×6 decking into a joist
only to hear a snap right before the screw sets...

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MAKING A PLUMB STICK

Posted by on 16/ 11/ 15

To plumb walls, you can make a plumb stick from any 2-ft. level and a straight 2×4 stud. Even a battered, inaccurate level can be used. Select the straightest stud you can find and nail a 16-in. 1×2 strip onto each end, letting the strips overhang the stud ends by about 3 in. Use some duct tape to attach a 2-ft. level to the op­posite edge of the 2×4 (near the center) and your plumb stick is nearly ready to use (see the photo below).

It’s important to check your plumb stick for accuracy. To do so, hold it vertical and flat against a wall. Keep the bottom end fixed in place as you move the top end back and forth until the bubble is exactly centered in the vial. Make pencil marks on the top and bot­tom of the wall along the 1x extensions...

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External Sources

Posted by on 16/ 11/ 15

To some extent, contaminants occurring on the road surface or in the road area have other sources than the traffic or the road. Such sources may be either local or remote.

mm/day

Fig. 6.2 Estimates of pollution concentrations in snow banks along a highly trafficked city road (AADT 40 000) as a function of the intensity of snowfall (expressed as mm of water) (B^kken, 1994b)

Local sources may include agricultural and industrial activities, dust and runoff water from buildings, e. g. copper-plated roofs, and heating by oil, coal and wood. Pollutants include particles, heavy metals, micro-organic pollutants, pesticides, or­ganic carbon and compounds containing nutrients...

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With a Frequency Relation

Posted by on 16/ 11/ 15

Consider Example 3.2 in which the annual maximum flood peak discharges over a 15-year period on the Boneyard Creek at Urbana, Illinois, were analyzed. Suppose that the annual maximum floods follow the Gumbel distribution. The estimated 25-year flood peak discharge is 656 ft3/s. It is not difficult to imag­ine that if one had a second set of 15 years of record, the estimated 25-year flood based on the second 15-year record likely would be different from the first 15-year record. Also, combining with the second 15 years of record, the esti­mated 25-year flood magnitude based on a total of 30 years of record again would not have the same value as 656 ft3/s...

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Snow and Ice

Posted by on 16/ 11/ 15

In regions with a cold climate, snow and ice may cover the road surface for a period. Various machinery is used to clear roads of snow. On icy surfaces, sand or grit may be used to increase the friction. For de-icing purposes, road salt is used, mostly NaCl. The salt makes the road wet, thus keeping more of the pollutants on the road surface with potential to leak into cracks in the road surface and along the road shoulder.

If let lying for an extended period of time, snow deposited along roads often becomes heavily loaded with traffic pollutants via splash and spray. The deposition rates of pollutants to the snow banks along heavily trafficked roads may be high (Table 6.4). The resulting concentrations in the snow banks may also be high but depend on the amount of snowfall (Fig. 6.2)...

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