книги / Interpreting in the Construction Industry Geotechnics and Underground Construction

Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain. Typically made from polypropylene or polyester, geotextile fabrics come in three basic forms: woven, needle-punched, or heat-bonded.

The most important property of geotextiles used for the production of GCLs is their durability. They have to resist the highly alkaline chemical environment of the bentonite and the chemistry of the water, in some cases leachate. Polypropylene (PP) and polyethylene of high density (HDPE) meet this requirement. So plastics of these types are commonly used for the upper and lower layers of GCLs.

Make the antonyms of woven and permeable using the negative prefixes non- and im-.

Check yourself using a dictionary.

Task 7. Read the text and draw a mind map detailing the key characteristics and benefits of geosynthetic clay liners in English and Russian:

Memorize the following:

Geosynthetic Clay Liners (GCLs) have become popular in landfill engineering as an alternative to traditional compacted clay liners.

GCLs consist of layers of geosynthetics surrounding a layer of low-permeability sodium bentonite. The materials are needlepunched together into a lining material capable of resistance to high shear forces between bentonite and textile envelope.

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Bentonite is a mixture of minerals composed mainly (up to 90%) of montmorillonite, the least permeable of all the clay minerals. Bentonite is a volcanic clay mineral that formed naturally during the course of 200 million years under the influence of water and pressure.

The excellent swelling capacity of bentonite when it comes into contact with moisture is responsible for the quick and reliable sealing effect of GCLs.

Due to environmental laws, any seepage from landfills must be collected and properly disposed of, otherwise contamination of the surrounding ground water could cause major environmental and/or ecological problems. The lower the hydraulic conductivity, the more effective the GCL and geomembranes will be at retaining seepage inside of the landfill.

Task 8. Work in pairs. Take turns to read out loud and interpret the following sentences:

1.Geotextile fabric can be installed underneath geogrids for roadway stabili-

zation.

2.Our geotextiles are used as reinforcing layers to allow the most cost effective construction of walls.

3.Permeability is a mathematical constant (k) determined by measuring water flow through a soil or other layer under a prescribed set of conditions.

4.Permeability is essentially synonymous with hydraulic conductivity, although this term may be more strictly interpreted as correct only if a liquid is the permeant.

5.The authors also conducted shear test on GCLs.

6.Non-reinforced GCLs are either geotextile-related, geotextileand poly- mer-related or geomembrane-related. These liners have geotextiles on both surfaces or geomembrane instead of geotextile on one surface.

7.Bentonite is primarily composed of montmorillonite, a high swelling clay.

8.The results showed that it gives even better performance improvement with respect to bearing capacity.

Task 9. You are at a geosynthetics conference. Your fellowmate reads out loud, you make notes and interpret:

Memorize the following:

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A. GSE Tri-AxialGeonets are synthetic drainage materials manufactured from the highest quality high-density polyethylene (HDPE). They are designed to transmit fluids and gasses uniformly under many in-situ conditions.

Tri-Axial Geocomposites consist of a geonet heat-bonded with a nonwoven nee- dle-punched geotextile, and are designed to provide drainage filtration to keep silt and soil particles from clogging the flow or to increase the friction characteristics.

Memorize the following:

Normal stress – здесь: нормальное напряжение

B. Geosynthetic Clay Barriers are manufactured hydraulic barriers. The mineral component usually consists of bentonite. The aim of this study was to establish the influence of swelling on mechanical properties of bentonites. For this purpose, granular bentonite clay was chosen for laboratory testing. Its mineralogical composition was predominantly montmorillonite (80%-85% by mass). The correlation between swelling and water content on one side and changes in shear strength on the other side were tested. During several series of testing, different levels of swelling of bentonite were simulated under the conditions of changing normal stress and hydration times. Swelling behaviour of bentonite was determined through long-term swelling tests using oedometer. Shear strength testing shows decreasing cohesion with longer hydration of bentonite. The friction angle increases with hydration that lasts from 7 to 14 days. There is no significant change in the friction angle with hydration time longer than 14 days.

Task 10. Interpret paying attention to rendering the following terms:

1.This shear force can be calculated by multiplying the cohesive shear strength by the area of the shear plane.

2.Friction is included in the measured shear force.

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3.Essential concepts of shear strength testing and shear stress-displacement behavior are presented.

4.Then the shear strain was calculated.

5.This involves solving the following set of governing equations: (i) straindisplacement relations, (ii) stress-strain relations.

Task 11. You are an interpreter at a construction industry conference. Your fellowmate reads out loud, you make notes and interpret. Then exchange your roles:

A.The engineering function of a GCL is containment as a hydraulic barrier to water or other liquids and sometimes gases. As such, they are used as replacements for either compacted clay liners or geomembranes, or they are used in a composite manner to augment the more traditional liner materials. The ultimate in liner security is probably a three component composite geomembrane/geosynthetic clay liner/compacted clay liner which has seen use as a landfill liner on many occasions.

B.Geosynthetic Clay Liners (GCLs) are geotextile and bentonite composites (typically sodium bentonite sandwiched between two layers of geotextile) engineered for a variety of environmental containment applications. The geotextiles offer a long lasting resistance to physical or chemical break-down in harsh elements, while the bentonite’s high swelling capacity and low permeability provide an effective hydraulic seal (and self-healing).

AFTERTASK ACTIVITY.

Look through the texts together with your fellowmate, find unknown words and look up their translations in dictionaries. How did you guess their meanings while interpreting?

Task 12. Translate from Russian into English in the written form:

Memorize the following:

Bentomat (Бентомат) – гидроизоляционный бентонитовый материал (ГБМ), отличающийся высокой эффективностью, надежностью и многофункциональностью. Структура данного материала основывается на бентонитовом

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грануляте, помещенном между слоев тканого и нетканого геотекстильного полотна. Принцип действия ГБМ заключается в способности натриевого бентонита разбухать и увеличиваться в объеме в 14–16 раз.

Применение:

Гидроизоляция дамб, плотин и каналов (в том числе подводная).

Экранирование хвостохранилищ.

Гидроизоляция подземных сооружений, фундаментных плит.

Экранирование автомагистралей и железных дорог.

Экранирование объектов по хранению нефтепродуктов, продуктов химической промышленности, промышленных отходов и других веществ.

Защита грунтовых вод.

Task 13. Work in pairs. Take turns to read out loud and interpret Task 12 into English. Compare your interpretations.

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SUPPLEMENT

Основные обозначения характеристик грунтов

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