Drilling pattern design

 

 

The drilling pattern ensures the distribution of the explosives in the rock, the desired blasting result, and the optimum drilling and blasting economics. Several varying factors must be taken into account when designing the drilling pattern: the rock drill ability and blast ability, the type of explosives, blast vibra-tion restrictions, and accuracy requirements of the blasted wall etc. Since every mining and construction site has its own characteristics, the drilling pattern is designed specially to it.

Many mines and excavation sites still plan their drilling patterns manually, but modern computer programs are also widely used, and they facilitate to mod-ify the patterns and predict the effect of changes on drilling, charging, loading and production. Drilling pattern design in tunneling and drifting is based on the following factors: tunnel dimensions, tunnel geometry, hole size, final quality requirements, geological and rock mechanics conditions, availability of explo-sives and means of detonation, expected water leaks, vibration restrictions, drill-ing equipment. Miners typically have several variations of drilling pattern to take into account the changing conditions along each tunnel. Drifting in mines is carried out with 5 to 10 drilling patterns for different tunnel sizes (production drifts, haulage drifts, draw points, ramp etc.). When designing a drilling pattern, the main aim is to ensure the optimum number of correctly placed and accu-rately drilled holes.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тесту:

 

a) Why are the rock drill ability and blast ability very important for drilling pattern design?

b) How do computer programs help in designing a drilling pattern?

 

c) What is the main aim when designing a drilling pattern?

 

3. Переведите на английский язык следующие предложения:

 

a) Выбор (choice) бурильного оборудования и количества ВВ

 

в значительной степени зависит от буримости и взрываемости породы.

 

b) При буровзрывных работах должен учитываться ряд (number) важ-ных факторов.

c) Для каждого рудника проектирование буровзрывных работ осуще-ствляется индивидуально.

 

TEST № 9

 

 

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Drainage and pumping

 

 

Mine working place must be kept dry. Water can flow into the underground mine from the water-bearing strata or from the surface through the fissures and voids in the rock. Flushing water from rock drilling also accumulates in drift bottoms. Surface water is kept out of the shaft by building around the shaft sills of the material taken out during sinking. Ground water leaks continuously, through fissures in the rock. Ditches are dug with some slope, the water col-lected and channeled by self-flowing to water basins at lower levels. The quan-tity of the mine waters changes with season of the year and with the advancing of mining operation. In the mines with the threat of flooding, the special isolat-ing measures are taken.

 

There is a pump station with its high-pressure pumps, which lifts under-ground water to surface through the pipe system. The water pumped from the shaft is carried far away from the shaft to prevent the water from returning. Wa-ter within a comparatively short distance from the surface can be drained from the shaft by sinking a well or small shaft adjacent to the main shaft. Sump is a water basin at the bottom of a shaft, in which water is also collected and from which it is pumped.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

a) Where from can water flow into the underground mine?

 

b) How do ground waters move down to the water basin? с) What is sump?

 

3. Переведите на английский язык следующие предложения:

 

a) Осушение рудника – очень важная часть горных работ.

 

b) Воды поступают в рудник через трещины и пустоты породы.

 

с) Источники воды в руднике – поверхностные воды, грунтовые воды

 

и промывные воды.

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TEST № 10

 

 

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Ventilation

 

 

Ventilation of the mine is vitally important task. A sufficient amount of air must be provided to keep the lower levels of mine well ventilated. Air quality in mine workings must be kept at acceptable health standard. The air in mine is regularly contaminated by smoke from blasting and exhaust from diesel pow-ered machines.

The mine needs a ventilation system, and usually it is induced ventilation with high-pressure fans on surface, blowing fresh air down through the intake shaft. There is a network of ventilation ducts in the mine. To regulate the direc-tion of airflow for its needed distribution into the underground workings, special devices are installed. They are ventilation doors, ventilation dam (stopping) to control the airflow, passing through active work areas. Then an exhaust airway channels the polluted air away from under-ground workings. It is very important to provide enough of fresh air directly to the stope, and prevent the loss of fresh air by shortest way between intake and exhaust airways. The duty of special ventilation department is the control of mine atmosphere, inspection and main-tenance of ventilation devices, isolation of ventilation ducts against air loss.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

a) Why is ventilation of mine so important?

 

b) What is air in mine regularly contaminated by?

 

c) What are the main components of mine ventilation system?

 

3. Переведите на английский язык следующие предложения:

 

a) Вентилятор – любое устройство или машина, создающее поток воз-

 

духа для проветривания.

 

b) Основными загрязнителями (pollutants) рудничной атмосферы яв-ляются дым от буровзрывных работ и выхлопные газы.

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c) Вытяжной воздуховод удаляет загрязненный воздух, а приточный обеспечивает доставку свежего воздуха.

 

TEST № 11

 

 

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Rock bolting

 

 

Rock bolting is one of the most common methods of rock reinforcement. Rock bolting is also an inexpensive and uncomplicated way of limiting rock de-formation and holding rock pieces together. The main idea of rock bolting is to increase the ability of the rock to support itself and resist stress.

Bolting is normally done during or immediately after excavation, but it can also be done before excavation, especially when large rock masses need to be bolted. The amount of bolting, the frequency and type of bolt depend on the rock conditions, purpose, and lifespan of the excavated space. Bolts can be divided into categories according to the way they behave in the rock, grouted bolts and anchored bolts. They are also classed as temporary or permanent.

Anchored bolts are meant for temporary rock support. The bolt has an ex-panding anchor in its end. After insertion in the hole, it is rotated or pressed against the bottom of the hole. This expands the wedged bolt end, anchoring it firmly against the sides of the hole.

 

Задания

 

 

1. Переведите текст на русский язык.

 

2. Ответьте на вопросы к тексту:

 

a) What is the main idea of rock bolting?

 

b) When is the rock bolting usually done?

 

c) What categories of bolts do you know?

 

3. Переведите на английский язык следующие предложения:

 

а) Наиболее популярный и эффективный вид цементации – полимер.

 

b) Количество креплений, частота их установки и тип болтов зависят от качества породы, а также целей и продолжительности использования разрабатываемой площади.

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c) Анкерные болты используются для временного крепления.

 

 

TEST № 12

 

 

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