книги / Interpreting in the Construction Industry Geotechnics and Underground Construction

Radioactive Methods of NDT on Concrete

Radioactive methods of testing concrete can be used to detect the location of reinforcement, measure density and perhaps establish whether honeycombing has occurred in structural concrete units. Gamma radiography is increasingly accepted in England and Europe.

The most common method of non-destructive field testing is through a process called sounding. Sounding involves striking the concrete surface and interpreting the sound produced. Solid concrete will produce a ringing sound, while concrete that is spalled, delaminated, or contains voids will produce a flat or hollow sound.

Sounding test of concrete is accomplished using a variety of tools. Sounding of small areas and vertical or overhead structural elements is best achieved by using a hammer or steel rod. A steel chain can also be dragged over the surface under evaluation. This method is best suited for slab surfaces where large areas can be tested in a reasonable amount of time.

Non-destructive evaluations is also conducted using ultrasonic pulse velocity methods.

Two common approaches include a pulse velocity meter and an impact echo system. The pulse velocity meter can detect defects such as the depth of cracks and loss of bond. The impact echo system can detect the thickness of a thin concrete section, locate a crack within the concrete, and locate voids or defects such as honeycombing.

Ground Penetration Radar Survey (GPR)

Task 13. Read the text, find translation of new terms and translate the text at sight

ГЕОРАДАРНОЕ ОБСЛЕДОВАНИЕ

Георадарное обследование грунтов и объектов является современной неразрушающей технологией контроля, применяемой в строительстве и близких к строительству областях (георадиолокация, георадарная съемка, георадарное исследование, сканирование, зондирование и ещё ряд синонимов).

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Георадиолокационное обследование известно в двух возможных вариантах: это георадарное профилирование и георадарное зондирование.

Технический анализ прохождения излучаемых георадаром электромагнитных волн сквозь земную толщу и различные подземные коммуникации позволяет посредством данного метода видеть то, что скрывается под слоем горных пород на глубине до 100 метров. Благодаря возможности изменения частоты излучаемой волны георадар позволяет обнаруживать небольшие объекты на глубинах до 10 метров, а протяжённые подземные неоднородности – и на существенно больших глубинах. Георадарное обследование не требует много свободного пространства, метод эффективен и активно применятся в условиях городской застройки, где теснота сочетается с интенсивным движением транспорта и другими ограничивающими свободное перемещение факторами.

ЗАДАЧИ, ДЛЯ РЕШЕНИЯ КОТОРЫХ ИСПОЛЬЗУЕТСЯ ГЕОРАДАРНОЕ ОБСЛЕДОВАНИЕ:

1.Обнаружение действующих или не действующих коммуникаций и коллекторов разнообразного назначения;

2.Обнаружение подземных ходов, подвальных помещений, бомбоубежищ и т.п.;

3.Обнаружение подземных пустот и полостей, зон разуплотнений или трещин;

4.Измерение глубин заложения фундаментов, свай, дренажных систем, мостовых опор;

5.Обследование грунтового массива под фундаментами существующих зданий и сооружений;

6.Определение глубины залегания подземных вод;

7.Исследование полотна шоссейных дорог, взлетно-посадочных полос аэродромов, для оценки их состояния;

8.Изучение характеристик состояния грунтового массива для строительства сооружений;

9.Сканирование бетонных массивов с целью обнаружения пустот и трещин, поиска арматуры.

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Task 14. Look up the test types translation in the dictionary. Mind the abbreviations.

Different types of in situ tests

		Static Cone	Dynamic	Pressuremeter
	Vane test (VT)	Penetration Test	Penetration Test
				(PMT)
		(CPT)	(SPT)

(retrieved from S. Varaksin’s presentation)

Task 15

A.Watch the advertizing video Струйная цементация грунтов at https://www.youtube.com/watch?v=l85GubHvU3c (6:15) and look up all unknown terminology in the dictionary.

B.Interpret the video in turn with your partner.

Task 16.Watch the advertizing video Юг-Эксперт. Обследование конструкций зданий и сооружений at https://www.youtube.com/watch?v=ikC2G vLXGAs and interpret the information about different devices used for nondestructive tests.

Task 17

A.Watch the talk of С.Н. Савин «Методы испытания строительных конструкций зданий и сооружений» at a construction control conference at: https://www.youtube.com/watch?v=CThYYWk73_k and find unknown terminology in the dictionary.

B.Interpret the talk simultaneously in whisper to your partner.

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UNIT 3. TUNNELS AND TUNNELING METHODS

Task 1. Look at the picture below and outline roles envisaged for underground facilities:

Task 2. Look at the picture below and make a list of reasons for the tunnel collapse:

Task 3. Read the text and:

A.fill in the gaps _______ in the text with the words from the box below;

B.guess what the abbreviations Hp,Ht, B stand for (see Figure 1 and Table 1 below).

Memorize the following:

Rock load – нагрузка от скальных	Hard and intact rock – прочные и
грунтов (горное давление)	ненарушенные скальные грунты

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Rock condition – состояние скаль-	Blocky rock –	трещиноватые
ных грунтов	скальные грунты
Supporting system – крепь	Squeezing rock	– разрушенные
	скальные грунты
Rock mass – скальный массив	Loosened rock – рыхлые скаль-
	ные грунты

Factor, classification, Alps, rail, tunnel

Classification by Rock Load Factor (Terzaghi 1946)

Based on extensive experience in steel arch supported ______ tunnels in the

________, Terzaghi (1946) classified rock mass by means of the Rock Load ______________

(Hp). The rock mass falls into 9 classes from hard and intact rock to blocky and squeezing rock. The concept used in this classification system is to estimate the rock load to be carried by the steel arches installed to support a _________, as illustrated in Figure 1 of the next task. The

____________ is presented in Table 1.

Figure 1 – Movement of loosened rock around tunnel (Terzaghi, 1946)

Task 4. A. Match the rock mass types according to Terzaghi and their translations. For example, number … – letter...:

1) hard and intact rock	А. прочные слоистые или сланцевые
	скальные грунты
2) hard stratified rock or schistose	Б. среднетрещиноватый	скальный
	грунт
3) moderately jointed rock	В. прочные и ненарушенные скальные
	грунты
4) moderately blocky, seamy and	Г. полностью разрушенный скальный
jointed rock	грунт
5) very blocky and seamy, shattered	Д. слаботрещиноватый	скальный
	грунт
6) completely crushed	Е. сильнотрещиноватый	скальный
	грунт
7) squeezing rock at moderate depth	Ж. набухающий скальный грунт

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8) squeezing rock at great depth		З. разрушенный скальный грунт на
		небольшой глубине
9) swelling rock		И. разрушенный скальный грунт на
		большой глубине
	KEY: 1C, 2А, 3B, 4E, 5F, 6D, 7H, 8I, 9G.

B. What kind of support is needed for each rock type?

Table 1

A high-level overview of the rock load factor classification by Terzaghi and supporting system

	Rock Condition	Rock load Hp (ft)	Supporting
			System
	Hard stratified rock	0 to 0.5B	Light support
	Moderately blocky	0.25B to 0.35B (B+Ht)	No side pressure
	and seamy
			Considerable side pressure,
	Completely crushed	1.10 (B+Ht)	circular ribs (кольцевые ребра
			жесткости) are required
			Heavy side pressure,
	Squeezing rock	2.1 to 4.5 (B+Ht)	invert struts (распорки
	at great depth		обратного свода)
			and circular ribs are required

Task 5. Take turns to read out loud and interpret the following lines. Name the terms which are irrelevant in this case; which industry do they refer to?

1)loosened rock – rock load – completely crushed – very blocky and seamy – shattered rock – passenger train configurations

2)swelling rock – rock condition – hard stratified rock or schistose – squeezing rock at moderate depth – diesel and electric locomotives

3)squeezing rock at great depth – hard rock – intact rock – locomotives and attached railroad cars – moderately jointed rock

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4)moderately blocky, seamy and jointed rock – freight and passenger trains – rock mass – completely crushed – supporting system

5)hard stratified rock – high-speed railways – very blocky and seamy – moderately blocky and seamy – squeezing rock

6)rock load – rock load factor – steam, diesel and electric locomotives – Terzaghi’s classification – from hard and intact rock to blocky and squeezing rock – steel arches

Task 6. Arrange the information about the NATM = New Austrian Tunneling Method logically and put down the respective number opposite each sentence except for Sentence 1:

Memorize the following:

	tunneling method – способ проходки		terrain’s inherent resistance and
	туннелей		support capacity – внутренняя
			устойчивость грунта и несущая
	blasting – взрывные работы
			способность крепи
	pre-supported tunneling method – способ		cohesion – сцепление
	проходки туннелей с предварительным
	укреплением
	sprayed shotcrete – торкрет-бетон		to stabilize – делать устойчивым
	(набрызг-бетон)
The New Austrian Tunneling Method (NATM)
a) The New Austrian Tunneling Method, the world’s most widely used				1)
underground construction method, partially owes its success to the
technical breakthroughs in shotcrete technology over recent years.
b) NATM seeks to maximize the terrain’s inherent resistance and				…
support capacity, and is widely recognized as one of the most econom-
ical techniques for building and evaluating tunnels.
c) Developed by Ladislaus von Rebecewitz			in Austria in 1946 and	…
known as NATM, this system of tunnel engineering is more a set of
principles or a philosophy than a prescriptive, technical method.

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…

d) The resulting tunnel is covered with a layer of sprayed concrete or shotcrete, which is faster and easier to execute than traditional formwork. The shotcrete layer increases the internal cohesion of the rock mass, reinforcing the support ring, and can act as a temporary as well as final lining, depending on the site’s requirements.

e) Unlike the classical methods such … as the Belgian or German approaches,

where the tunnel is immediately supported without allowing it to deform naturally, NATM allows the deformation of the rock mass before stabilizing the tunnel, which reduces the amount of additional support materials required (see the figure Deformation curve of the rock mass).

KEY: a)1; b)3; c)2; d)5; e)4 .

A.What is the difference between the NATM and conventional presupport tunneling methods?

B.Take turns to read out loud and interpret the logically arranged text in Task 6.

Task 7. Which picture shows the NATM technology? Which one depicts the conventional pre-support tunneling method?

…					…
					Pre-nailing
	Rockbolt	Non-reinforcement					Reinforcement
	support effect				support effect		effect
							Transverse and lon-
							gitudinal arching
							effect

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Task 8. A. Put down the relevant terms from the box opposite respective pictures and descriptions:

tunnel excavation; rock bolt support; nailing, pre-nailing; grouting, jet grouting

1

2
	Soil nailing consists of the passive reinforcement of existing ground by in-
	stalling closely spaced steel bars (i.e., nails), which may be subsequently en-
	cased in grout.
	As construction proceeds from the top to bottom, shotcrete or concrete is also
	applied on the excavation face to provide continuity.
	In a soil-nailed retaining wall, the properties and material behaviour of three
	components – the native soil, the reinforcement (nails) and the facing element –
	and their mutual interactions significantly affect the performance of the structure.
3	The rock mass is a significant barrier in
	itself. However, as it is a discontinuous
	material, its hydraulic characteristics may
	vary widely, from an impervious medium
	to a highly conductive zone. As a conse-
	quence, for groundwater control, it is nor-
	mally standard procedure in Norwegian
	tunnelling to include pre-grouting for the
	purpose of reducing the permeability as
	well as consolidating the rock mass.
	Thus, jet-grouting is a trenchless method that utilizes grout to stabilize ground
	conditions within a project site.

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4

A rock bolt is a long anchor bolt, for stabilizing rock excavations, which may be used in tunnels.

This NATM consists of the installation of passive steel reinforcement in the rock (e.g., rock bolts) followed by the application of reinforced shotcrete.

B. Memorize the following:

tunnel excavation – проходка туннеля	transverse arching effect – поперечный
	арочный эффект
rock excavation – разработка скального	longitudinal arching effect – продоль-
грунта	ный арочный эффект
rock bolt support – анкерная крепь	retaining wall – подпорная стенка
nailing – гвоздевание	reinforced shortcrete – армированный
	торкрет-бетон
pre-nailing – предварительное гвозде-	jet grouting – струйная цементация
вание

С. Take turns to read out loud and interpret the information from 8A.

Task 9. A. Fill in the gaps with appropriate words from the Memorize the following section:

	Memorize the following:
stress-strain		напряжение-деформация
induced stress		действующее напряжение
charge weight		здесь: вес заряда (при взрывных
		работах по проходке туннелей)
tensile stress		растягивающее напряжение
tensile force		растягивающее усилие
tensile force point		точка приложения усилия растяжения
tensile strength = traction		прочность на растяжение

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