Научная статья на тему 'Pile foundations in the constructed conditions of the city'

Pile foundations in the constructed conditions of the city Текст научной статьи по специальности «Строительство и архитектура»

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Ключевые слова
PILOT / INJECTION / CARRYING CAPACITY / SEDIMENT / GROUND / MODEL RESEARCH / NATIONAL EXPERIMENT / INTERACTION / CALCULATION / COEFFICIENT

Аннотация научной статьи по строительству и архитектуре, автор научной работы — Karpyuk V.M., Karpyuk I.A., Pancheva N.V.

This article highlights the problem of foundations in constrained urban environments, and also describes the results of laboratory tests in a pile model of piles, which are immersed by the method of driving and indentation.

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Текст научной работы на тему «Pile foundations in the constructed conditions of the city»

of South Koreans surveyed (81%), 79% of Japanese and 74% of US residents doubt the reliability and safety of unmobiles.

In Russia, 51% agreed with the statement: "I would like to have my unmanned vehicle." All over the

world, they are 42%. The least willing to acquire this type of transport - in Germany (24%). According to the survey results, only 15% of Russians said they would not use an unmanned vehicle (Fig. 17).

B. 2. Какое из приведённых ниже утверждений отражает ваше мнение?

• Я хочу поскорее начать пользоваться беспилотным автомобилем

• Я не уверен(а), но идея появления беспилотных автомобилей кажется мне интересной

• Я против появления беспилотных автомобилей, никогда не буду ими пользоваться

Figure 17.

Unmanned vehicles can be a revolution of vehicles and completely change the lives of people. How this technology will evolve will show time.

References

1. https://habr.com/post/395601/.

2. https://habr.com/post/395663/.

3. https://habr.com/post/393237/.

4. https://goo.gl/Atg4ad

5. https://goo.gl/69JnSr

6. https://goo.gl/4bmAL3

7. https://goo.gl/dHievU

Pile foundations iN THE CONSTRUCTED CONDITIONS OF THE CITY

Karpyuk V.M.,

Professor of the Department of concrete and masonry structures; Odessa State Academy of Building and Architecture, Odessa, Ukraine

Karpyuk I.A.,

Associate professor, candidate of engineering sciences, faculty of hydrotechnical and transport building;

Odessa State Academy of Building and Architecture, Odessa, Ukraine

Pancheva N. V. student;

Odessa State Academy of Building and Architecture, Odessa, Ukraine

ABSTRACT

This article highlights the problem of foundations in constrained urban environments, and also describes the results of laboratory tests in a pile model of piles, which are immersed by the method of driving and indentation.

Keywords: pilot, injection, carrying capacity, sediment, ground, model research, national experiment, interaction, calculation, coefficient.

In recent years, more and more often there is a need for the construction of residential and civil buildings adjacent to existing buildings and structures. In such conditions, the use of piles, immersed by driving or vibration, is dangerous, since, in this case, there are dynamic effects from which damage occurs in the structures of existing buildings. Thanks to the joint fruitful work of scientists and builders, a number of technologies and mechanisms have been developed in

the cities of St. Petersburg, Moscow, Kiev, etc., allowing plunging prismatic piles [1, 5, 7, 8]. This issue was addressed by such scientists as: Abelev M.Yu., Dalma-tov B.I., Gdalin S.V., Simagin V.G., Sotnikov S.N., Shvets V.B., Ginzburg L.K., Koval V.E., Feklin V.I. and etc.

The problem of construction in cramped urban conditions is becoming more and more acute in Odessa.

Therefore, the actual question is the influence of the method of piling in specific engineering and geological conditions of the southern region.

This article is devoted to the study of the processes occurring in the soils of the pile foundation during its immersion.

Many factors affect the bearing capacity of pile foundations. These factors include: the design and geometrical parameters of the piles, the distance between them, the location of the piles in the bush and the method of their immersion.

These processes have been studied before, but mainly on penetrometers. Many scientists (Kerizel, Lerminye, Cheng, etc.) believe that penetrometers are piles of small diameter and data on their interaction with the foundation soils can be transferred with a certain accuracy to natural size piles. If we agree with this and compare the bearing capacity of the base, determined using a static penetrometer (S) with the bearing capacity of the base determined using a dynamic penetrometer (D), then from the ratio of these two values (S / D) we get the coefficient, which, according to various scientists fluctuates in large chapels (S/D)=0.5-1.5, which confirms the little studied of this issue.

Before conducting full-scale studies of piles, tests of their models in laboratory conditions were performed. The tests were carried out with the aim of studying the interaction of the piles with the ground of the base during their immersion by indentation and driving.

The tests were carried out in a tray. The front wall of the tray is made of glass for the possibility of observing layer-by-layer displacement of the soil in the process of immersing pile models.

The test method is as follows. The tray was filled with primer. A load was placed on the lower suspension, which was transmitted to the ground through the beam, thus creating domestic pressure corresponding to pressure in natural conditions. On the pile that was immersed installed top beam. On the upper suspension laid the load necessary for immersion pile indentation. Driving the pile into the pile was carried out using a device attached to the beam of the device. The device is a guide rod with a movable load. To determine the movement of soil in the tray before the test, deformation clamps were laid, which were laid in horizontal tracks with an interval of 1 cm vertically.

The piles were immersed in various soils (sand, sandy loam, loam) of the broken structure. The study of models of piles, immersed in various ways, was performed in soils of the same density and humidity [2, 3, 4].

Comparing the test results, it can be seen that the sealing zone of the near-winding space of the piles submerged by indentation and driving differs. Pile sealing area, submerged driving more than the pile compression area, immersed in the indentation. This pattern is better seen in soils with high humidity, and in those experiments where cohesive soils served as the basis.

At the device of driven piles, various methods of immersion are used: dynamic immersion or vibration immersion. When piling with diesel hammers or vibratory pile drivers in surrounding soils, vibrations occur. The impact of these fluctuations on nearby buildings or

structures can lead to their damage or destruction of structures as a result of additional uneven precipitation of the base, and direct impact on them. This is most clearly manifested in those cases when the foundation of foundations are weak, water-saturated clay soils that can be further consolidated under dynamic loads.

Taking into account the above, in some cases, it is advisable to apply the method of pressing in piles. This method was widely used in large cities of Kiev, Omsk, Leningrad, and Moscow, where special installations were developed for pressing in piles.

In Odessa, the installation developed by Stikon JSC with the scientific support of scientists from the Odessa State Academy of Civil Engineering and Architecture is successfully used for piling with indentation.

The installation consists of a base machine with a pile mast, a working body in the form of a rod with a headroom, mechanisms for lifting and pressing in piles. The lifting and pushing mechanism consists of two platforms that are interconnected by cables. One loading platform on a rail track with an automatic movement mechanism, fixed unit cassettes and loads. Another platform is rigidly fixed to the upper part of the stem, connected to the lifting mechanism and equipped with cassettes of moving blocks.

The principle of the installation is as follows. The cargo platform is installed on a rail track and loaded with weights. The pile is installed at the point of immersion, and the head of the pile is brought into the headgear. When you turn on the cargo winch through the burton system, the upper cargo platform approaches the lower platform, setting in motion the stem of the working body. The rod passes the pressing force through the cap onto the pile.

Employees OGASA and NIISK conducted tests, the purpose of which is to determine the bearing capacity of piles loaded with this installation. At one of the sites, tests were carried out on a prismatic pile with a section of 35x35 cm and a length of 15 m. The site is composed of the following IGEs: loess loess semisolid; loesslike sandy loam; loess soft-plastic loam; loess loamy fluid; loesslike loamy clay; semi-solid loam. The depth of immersion in the carrier layer (semi-solid loam) was 0.85 m.

The load during testing was brought up to one and a half times the calculated load on the pile and amounted to 1,100 kN. Piles were immersed in the difficult constrained conditions (from the axis of the pile to the nearest existing building 1.15m).

Depending on the features of the project, the location of the piles in the plan and the geotechnical conditions of the construction site, the indentation of the piles can be done in a point, linear and coordinate way. The point method is used for diving single piles, with a tape arrangement of stabilization and anchor piles, as well as piles of increased responsibility, in the case when the determining factor is ensuring the safety (security) of nearby buildings. The point method is effectively used in the restoration of foundations, in the conduct of pile work in conditions of maximum proximity to existing buildings, foundations and communications.

The example described above confirms that this method of piling is most appropriate for construction in

cramped parts of the city. However, it should be noted that the method of piling with indentation has not been studied well enough.

References

1. Dotsenko A.I. Excavation work in cramped conditions of transport construction. A.I. Dotsenko [Text] / A.I. Dotsenko. - Moscow: Transport, 1987.

2. Karpyuk V. M., Karpyuk I. A. Interaction of hanging prismatic pales with sandy soils / Karpyuk V. M., Karpyuk I. A. // Visnyk OFABA. - Whip 61. -Odessa: Znauzreklamservis LLC, 2016. - P. 137-141.

3. Karpyuk I.A. ,. Krishtopa S.N., Nikolyuk V.N. / The compaction zone around short prismatic piles in sandy soils // Visnyk ODABA No. 60 Odessa: bureau "Optimum", 2015 - P. 154-159.

4. Karpyuk I.A. Movchan O. M., Trufin M.D. Peculiarities of the interaction of models of hanging prismatic pallets with sandy soils / I.A. Karpyuk, O.M.

Movchan, MD Trufin // The Bulletin of the ODABA № 60 Odesa: the first issue of the "Optimum", 2015 - pp. 202-206.

5. Kopotilova AS Features of construction in a dense urban development, / Young scholar. - 2017 -№49. - P. 59-61. - URL https://moluch.ru/ar-chive/183/46924/ (referral date: 14.01.2018).

6. Problems of building high-rise buildings in conditions of dense urban development Sayadyan T.V., Shumeev P.A., Sheina S.G. Actual problems of technical sciences in Russia and abroad/ Collection of scientific works on the results of the international scientific-practical conference. No. 2. Novosibirsk, 2015. 162 p.

7. Simagin V.G. Design and construction of foundations in the vicinity of existing structures in dense buildings [Text] / V.G. Simagin - Moscow: Associations of Construction Universities, 2010. - p. 52

ВЛИЯНИЕ НЕОПРЕДЕЛЯЕМОЙ ВЛАЖНОСТИ НА ЭЛЕМЕНТНЫЙ СОСТАВ ЛЕТУЧИХ ПРИ

ПИРОЛИЗЕ ДРЕВЕСИНЫ

Левин А.Б.,

доцент, кандидат технических наук, Лопатников М.В.,

Московский государственный технический университет им. Н.Э.Баумана Мытищинский филиал, доцент, кандидат технических наук

Хроменко А.В.

Московский государственный технический университет им. Н.Э.Баумана Мытищинский филиал, доцент, кандидат технических наук

INFLUENCE OF UNEVIDENT MOISTURE ON ULIMATE ANALYSIS OF VOLATILE MATTER AT

WOOD PYROLYSIS

Levin A.B.,

Associate Professor, PhD Lopatnikov M. V.,

Bauman Moscow State Technical University, Mytischi Branch,

associate Professor, PhD Khromenko A. V.

Bauman Moscow State Technical University, Mytischi Branch,

associate Professor, PhD

АННОТАЦИЯ

Исследовано изменение элементного состава летучих, образующихся при пиролизе древесины. Высказано предположение о наличии в сухой обеззоленной массе древесины неопределяемого стандартными методами содержания влаги, удаляемой из древесины до начала термической деструкции древесинного вещества. Предложен алгоритм расчета элементного состава летучих по мере изменения относительной массы твердого остатка. Представлены результаты расчетов атомных отношений (О/С) и (Н/С) по предложенному алгоритму. Показано, что влияние неопределяемой влаги существенно только в начальной фазе пиролиза при ng—0,8.

ABSTRACT

The change of the ultimate analysis of volatile matter formed during the pyrolysis of wood was studied. It was suggested that the dry, ash-free mass of wood have some unevident moisture content undetectable by standard methods, which is removed from the wood before the thermal decomposition of the wood substance. An algorithm for calculating the ultimate analysis of volatile matter as function of the relative mass of the solid residue is proposed. The results of calculations of atomic ratios (O/C) and (H/C) according to the proposed algorithm are presented. It is shown that the effect of undetectable moisture is significant only in the initial phase of pyrolysis with ng—0,8.

Ключевые слова: пиролиз древесины, выход летучих, элементный состав.

Keywords: wood pyrolysis, volatile matter, ultimate analysis.

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