Blog Archives

SLIDING DOORS

Posted by on 18/ 11/ 15
SLIDING DOORS
SLIDING DOORS
Подпись: Interior Door

Because they do not have to be sealed against the weather, interior doors are much simpler than exterior doors. Interior doors are used primarily for privacy and to control air flow. The doors themselves are typi­cally made of wood or composite wood products. They are 1% in. thick, and have either panels, like the one shown above, or a flush plywood veneer over a hollow core or solid core.

Hinged interior doors are usually prehung on a jamb without casings. The jamb on the hinged side is first nailed to the frame of the building, using shims to make it plumb. The jambs at the head and opposite side are then shimmed for proper clearance and nailed.

Some doors are hinged to a split jamb that will expand to accommodate some variation in wall thick­ness...

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The Nabatians of Petra, hydraulicians of the desert

Posted by on 18/ 11/ 15

Antigonus, the old one-eyed general of Alexandria, sought to solidify its domain in the Near East, between the domains of Ptolemy in Egypt and that of Seleucos in Mesopotamia. He coveted the wealth of the semi-nomad “barbarians” who frequented the routes of caravans carrying spices, myrrh, and incense from Maryab in Arabia Felix, to the south of the Dead Sea. In 312 BC, he sends his friend Athenes on an expedition toward the “formidable citadel”, the “rock” (petra in Greek) where these “barbarians” store their riches. Athenes does not come back alive. Antigonus then sends his son Demetrius to lay siege to Petra, again without success. Later, the Seleucids, new mas­ters of Syria, attempt the same exploit and also fail...

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ATTACHING THE MUDSILL

Posted by on 18/ 11/ 15

Builders may attach new mudsills at different stages of form assembly. But here are the essen­tials. Before nailing up the mudsill (to the bot­tom of the pony-wall studs) predrill for anchor bolts, as described earlier, making sure that no bolt occurs under a stud. If local codes require metal termite shields, tack them to the under­side of the mudsill after first predrilling it with anchor-bolt holes. Then, using a pneumatic nailer, end-nail the sill to the studs, using two 16d nails per stud. If there isn’t enough room to end-nail upward into the sill, jack the mudsill tight to the studs and toenail down from the studs into the mudsill.

Once the mudsill is nailed to the studs, insert anchor bolts into the predrilled holes, screw on washers and nuts, and tie the free ends of the bolts ...

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Time-Dependent Reliability Models

Posted by on 18/ 11/ 15

The development of hydrosystems engineering projects often includes the de­sign of various types of hydraulic structures, such as pipe networks for water supply, storm sewer systems for runoff collection, levee and dike systems for flood control and protection, and others. Generally, the system, once designed and constructed, is expected to serve its intended objectives over a period of several years, during which the system behavior and environmental factors could change with respect to time. In such circumstances, engineers often are interested in evaluating the reliability of the hydraulic structure with respect to a specified time framework...

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What Makes a Good Frame?

Posted by on 18/ 11/ 15

When most people choose windows, they begin by considering the frame material. They might be predisposed to traditional wood or low-maintenance vinyl. However, according to Nils Petermann at the Efficient Windows Collaborative, the most important factor to consider is the frame’s durability. This is where I’d like to refer you to an in­dependent organization that provides unbi­ased durability ratings for window frames. Unfortunately, there isn’t one.

You can make educated guesses about durability based on the frame material. But whether it’s wood, vinyl, fiberglass, alumi­num, clad, or composite, a well-constructed window lasts longer and performs better than a poorly constructed one regardless of the relative benefits of its frame material.

The best way to get a sense of window quality...

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REMOVING OLD FOUNDATIONS

Posted by on 18/ 11/ 15

To tear out an old foundation, you’ve got several options. All require safety glasses, hearing protec­tion, heavy gloves, a mask, patience, and a strong back. Before acquiring heavy and expensive equipment, try to break out a section of the old foundation using a 9-lb. sledgehammer and a 6-ft. pointed steel bar. Old concrete without rebar is often cracked and soft. Once you’ve removed a small section, the rest may come out easily.

If the concrete is too thick and hard, rent a towable air compressor and jackhammer. A 90-lb. jackhammer will break almost anything, but it’s a beast to maneuver; a 60-lb. hammer is light enough to lift onto a foundation wall and almost always strong enough to break a wall apart. A 60-lb...

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STEP2 Install the Gable Truss

Posted by on 18/ 11/ 15

The first truss to be installed is the gable truss (also called an end truss or a rake truss) that rests on the top plate of an end wall. This truss is usually built differently from regular trusses. Instead of having angled web pieces, these end trusses often have vertical webbing spaced 16 in. or 24 in. o. c. to allow for easy installation of sheathing or siding.

Some carpenters like to sheathe end trusses with OSB and even finish siding before raising them upright (see the photo below). Another option is to cut all the sheathing pieces on the ground, raise the truss, and then nail the pre­cut sheathing in place. It is certainly easier to sheathe a truss on the ground, but it makes the truss substantially heavier and more clifti-

4

cult to handle...

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Sampling Design

Posted by on 18/ 11/ 15

In establishing a monitoring programme and data collection schedule, the following points will need addressing. This is not a comprehensive list for every eventuality, but most monitoring programmes will need to consider this list as a minimum:

• The equipment, skills, storage and transportation facilities (and, if required, power to the site):

о Sampling, transport and storage protocols should be obtained or prepared to promote good practice and consequently to yield reliability of readings ob­tained from tests.

о A responsible person should be identified for sample collection and instru­ment readings and made available over the life of the programme. о Health and safety plans are required for personnel engaged in the sampling.

• Timing of sample collection:

о Sometimes a frequen...

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Data Storage and Retrieval

Posted by on 18/ 11/ 15

An appropriate database / record keeping system must be provided (or constituted):

• To hold the data.

• To have data extracted/interpreted in a manner that has meaning. There is no point in collecting data that cannot be successfully accessed.

• To allow it to be interrogated in a way that permits the likely users (owners, regulators, researchers, etc.) to apply the method of interpretation that meets their needs. As most data storage is archived electronically, consideration should also be given to providing secure network access.

• To be easily maintained and amended.

• To have some semi-automatic processing capability that will alert the database owner to take some investigative action if the data contained seems to indicate a problem...

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Second-Order Reliability Methods

Posted by on 18/ 11/ 15

By the AFOSM reliability method, the design point on the failure surface is identified. This design point has the shortest distance to the mean point of the stochastic basic variables in the original space or to the origin of standard­ized normal parameter space. In the AFOSM method, the failure surface is locally approximated by a hyperplane tangent to the design point using the first-order terms of the Taylor series expansion. As shown in Fig. 4.14, second – order reliability methods (SORMs) can improve the accuracy of calculated re­liability under a nonlinear limit-state function by which the failure surface is approximated locally at the design point by a quadratic surface. Literature on the SORMs can be found elsewhere (Fiessler et al., 1979; Shinozuka, 1983;

Breitung, 1984; Ditlev...

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