Round tower in Sydney’s Australia square

Constructed a few blocks from Sydney’s beautiful harbor, the Australia Tower, a 50 storey, 602 ft. high, lightweight concrete office building, dominates the business section of the city. The tower cost 30.24 million and was completed in 1967.

The tower, 135 ft. in diameter, provides an area of 14,225 sq. ft. per floor. A circular service core at the center incorporates all services, including 17 elevators in three banks.

Reinforced lightweight concrete was used for 88 percent of the project.

The structural spine of the tower consists of 22 exterior columns with a central service core made like a double-walled chimney connected with 20 radial walls forming 20 cells. Seventeen cells are for elevator shafts, and three are entrances to the service center core. The outside diameter of this circular wall system is 61 ft. 6 in.

Reinforced concrete was used throughout fir beams and slabs in the main system outside the service core.

Precast formwork — to form the outer skin of the columns and upturned and down-turned spandrel beams — was tied by bolts and welded stirrups to the monolithic on-site structures, which was cast against the outer skin. Plywood was used for the inner skin.

This tying-in procedure enabled the precast formwork, finished in white quartz chip, to become part of the stressed structure in the same way that reinforcing bars become stressed with the on-site concrete.

Lightweight concrete was also used for the basement and plaza slabs, which did not have expansion or shrinkage joints. The slabs were cast in three sections with shrinkage gaps for 4 months between placements. Then gaps were filled.

The tower’s first five levels are of flat plate construction for service flexibility and reduced floor-to-floor height.

 

EXERCISES

I. Read the text and translate it. Note the main building materials and structural elements mentioned in the text. Memorize them.

II. Give definitions of the following words:

reinforced concrete; beam; column; bar; structure; shrinkage; gap; flexibility.

 

 

SCOTLAND ’S LARGEST SUPERMARKET

New supermarket was recently opened at Cumbernauld.

The store, which is the largest supermarket in Scotland and the second largest in the U. K., is the centerpiece of the new Cumbernauld town shopping precinct.

The supermarket is a completely new answer to the problem of creating the most pleasant environment possible for busy shoppers.

A new specially designed ceiling has been installed which creates a sunny and inviting atmosphere, completely outdating the oppressive strip lighting generally found in supermarkets.

This, together with new ideas in the whole design and layout of the public areas, for example, signs indicating the whereabouts of foodstuffs which can be read by customers from all parts of the building, will make housewives’ shopping expeditions effortless and harmonious.

Every part of the 14,500 sq. ft. building, including the snack bar and the off-sales area, has been designed to ensure the highest standards of hygiene.

The construction and the finishes used allow thorough cleaning and maintenance, and the layout of the building gives freedom of shopper circulation and flexibility in display.

All the Galbraits shops throughout the Clyde Valley are usually recognizable as being part of the same organization.

 

EXERCISES

I. Read the text; translate it into Russian.

II. Speak about new ideas in the design of the building.

 

MODERN BRIDGE DESIGNS

There are six basic bridge forms: the beam, the truss, the arch, the cantilever, the cable-stay, and the suspension. A beam bridge is made of long timber, metal, or concrete beams anchored at each end. If the beams are arranged in a lattice, such as a triangle, so that each shares only a portion of the weight on any part of the structure, the result is a truss bridge.

An arch bridge has a bowed shape causing the vertical force of the weight it carries to produce a horizontal outward force at the ends. It may be constructed of steel, concrete or masonry

A cantilever bridge is formed by self-supporting arms anchored at and projecting toward one another from the ends; they meet in the middle of the span where they are connected together or support a third member.

In a cable-stayed bridge, the roadway is supported by cables attached directly to the supporting tower or towers. This differs from a suspension bridge where the roadway is suspended from the vertical cables that are in turn attached to two or more main cables. These main cables hang from two towers and have their ends anchored in bedrock or concrete.

The modern era of bridge building began with the development of the Bessemer process for converting cast iron into steel. It became possible to design framed structures with greater ease and flexibility. Single-piece, rolled steel beams can support spans of 50 to 100 ft. (15–30 m), depending on the load. Larger, built-up beams are made for longer spans; a steel box-beam bridge with an 850 ft. (260 m) span crosses the Rhine at Cologne.

Movable bridges. They are generally constructed over waterways where it is impossible or prohibitive to build a fixed bridge high enough for water traffic to pass under it. The most common types of movable bridge are the lifting, bascule, and swing bridges. The lifting bridge, or lift bridge, consists of a rigid frame carrying the road and resting abutments, over each of which rises a steel-frame tower. The center span in existing bridges is as long as 585 ft. (178 m) and is hoisted vertically. The bascule bridge follows the principle of the ancient drawbridge. It may be in one span or in two halves meeting at the center. It consists of a rigid structure mounted at the abutment on a horizontal shaft, about which it swings in a vertical arc. The lower center span of the famous Tower Bridge in London is of the double-leaf bascule type. Because of the need for large counterweights and the stress on hoisting machinery, bascule bridge spans are limited to about 250 ft. (75 m). The swing bridge is usually mounted on a pier in midstream and swung parallel to the stream to allow water passage.

Military bridges. In wartime, where the means of crossing a stream or river is lacking or a bridge has been destroyed by the enemy, the military bridge plays a vital role. Standard types of military bridges include the trestle, built on the spot by the engineering corps from any available material, and the floating bridge made with portable pontoons.

Pontoon. It is one of a number of floats used chiefly to support a bridge, to raise a sunken ship, or to float a hydroplane or a floating dock. Pontoons have been built of wood, of hides stretched over wicker frames, of copper or tin sheet metal sheathed over wooden frames, of aluminum, and of steel. The original and widespread use was to support temporary military bridges. Cyrus the Great built (536 B.C.) the earliest pontoon bridge in history, using skin-covered pontoons. However, Homer mentions pontoon bridges as early as c.800 B.C. The U.S. army began experimenting with rubber pontoons in 1846 and in 1941 adopted collapsible floats of rubber fabric with steel-tread roadways. At the same time the navy developed box pontoons of light, welded steel for ship-to-shore bridges during landing operations. These box pontoons could be assembled into bridges, docks, causeways and, by adding a motor, into self-propelling barges. Permanent civilian pontoon bridges have been built where the water is deep and the water level fairly constant or controllable, often also where the crossing is narrow or where the bottom makes it difficult to sink piers. The modern permanent pontoon is composed of many compartments, so that if a leak occurs in one compartment, the pontoon will not sink. Permanent pontoons are fastened together and several anchors are dropped from each. Often a section of a bridge built on them can swing aside to let a ship pass.

Several pontoon bridges have been built across the Mississippi River. Pontoons for raising sunken ships are watertight cylinders that are filled with water, sunk, and fastened to the submerged ship; when emptied by compressed air, they float the ship to the surface. A pontoon lifeboat consists of a raft supported by watertight cylinders.

VOCABULARY NOTES

beam bridge балочный мост

cantilever bridge консольный мост

cable-stay bridge вантовый мост

suspension bridge висячий мост

bascule bridge раскрывающийся мост

draw bridge натяжной мост

trestle bridge эстакадный мост

lattice решётка

bowed shape дугообразная форма

abutment опора

EXERCISES

I. Read the text and answer the questions:

1. What are the basic types of modern bridges?

2. When did the era of modern bridge building begin?

3. Where are the movable bridges constructed?

4. What are the main types of movable bridges?

5. What types of military bridges can you name?

6. Where have permanent pontoon bridges been built?

7. How are they composed?

II. Make up a brief summary of the text using questions of ex. I as a plan.

III. Make up reports about the oldest and most famous bridges.

 

TEST I

I. Give the Russian for:

mortar

durability

to meet industrial requirements

equipment

research engineer

strength of material

solid mechanics

mold

pouring

scaffolding

to bend

brickwork

carpenter

span

construction site

II. Translate into Russian:

1. The properties of the concrete mix depend on the activity of the binding materials.

2. To reinforce ordinary concrete structures is to introduce steel rods in stretched zones of concrete elements.

3. Portland cement is manufactured by burning shale and limestone; aggregates such as sand and crushed stone can be easily obtained.

4. The importance of piled foundations in building and industrial construction as well as in civil engineering has increased considerably over recent years.

5. Concrete beams, floors, roofs, and wall panels may be precast for many types of structures.

6. Being brittle, concrete cannot withstand tensile stresses, and it cannot therefore be used in structures subjected to tensile stresses under load.

7. Construction of the bridge is divided into four elements: the pylon, the back span, the anchor beam and the deck.

8. The purpose of foundation is to carry the load of structure and spread it over a greater area, evenly and without undue settlement, to the ground beneath.

9. Selection of the cement alone doesn’t ensure concrete with the properties desired, which depend also on the choice of aggregates and mixes, the control of the quality of water added to the mix, and on a series of other factors.

10. Various methods of constructing reinforced concrete houses involve extensive use of large sections manufactured in heavily mechanized factories and erected at the site.

 

TEST II

I. Give the Russian for:

to insulate

water supply

tensile stress

curing

shrinkage

prestressed concrete

cracking

beam

bearing structure

cast in-site concrete

reinforcement

bar

density

dead load

binding materials

II. Translate into Russian:

1. Depending on the method of production, piles can be divided into two main types: cast in-situ concrete piles and prefabricated piles.

2. Concrete beams, floors, roofs and wall panels may be precast for many types of structures.

3. The floor beam may be sufficiently strong to carry the load on it, but its deflection may be so great that a plastered ceiling wold crack or the floor would vibrate.

4. The proper thickness for bearing walls depend on the loads and are determined by the safe stress allowed per square inch on the brickwork.

5. Brick basement walls should be at least as thick as the walls above them and never less than 12 in.

6. Until recent years there was a tendency to consider reinforced concrete as a method of construction suited to massive structures.

7. Buildings of reinforced concrete may be constructed with load-bearing walls or with skeleton frame.

8. If the weight of any building exceeds the bearing resistance of the material, either soil or rock on which it rests, the material will give way and the building will sink.

9. The foundations are spread out to distribute the load over the bed so that the safe bearing power of the bed per square foot is not exceeded.

10. Common bricks are very little used at the present time because they do not withstand the moisture and frost as well as stone or concrete.