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OF CONSTRUCTION MACHINERY

Ruslan Abdulov, applicant

Balakovo Institute of Technics, Technology and Management, Russia

Championship participant: the National Research Analytics Championship - "Russia";

the Open European-Asian Research Analytics Championship;

Outlined the main problems and propose approaches that improve the technical equipment of the building.

Keywords: technical equipment, park construction machinery, construction machinery settings

 

Good project management in construction must vigorously pursue the efficient utilization of labor, material and equipment.Improvement of labor productivity should be a major and continual concern of those who are responsible for cost control of constructed facilities. Material handling, which includes procurement, inventory, shop fabrication and field servicing, requires special attention for cost reduction. The use of new equipment and innovative methods has made possible wholesale changes in construction technologies in recent decades. Organizations which do not recognize the impact of various innovations and have not adapted to changing environments have justifiably been forced out of the mainstream of construction activities.

Construction Machinery Maintenance Cost and Problems are. Maintenance costs for Fleets of Vehicles and Specialized Machines are making a big dent as a portion of the operating cost at Construction and Transportation companies. Because of this, some are Not providing the right level of Maintenance to their Equipment, this can have an even worse effect.

Contractors are Suffering! The Construction Industry is today more competitive than ever before, usually the high number of bids for a job makes companies bring the prices to a point where they barely "break even".

What has happened? High Capital Investment, Materials, Fuels, and Labor on the rise; and some high Maintenance Overhead, are frequently outweighing the revenue today.

Break that Tradition! The selection of the appropriate type and size of construction equipment often affects the required amount of time and effort and thus the job-site productivity of a project.It is therefore important for site managers and construction planners to be familiar with the characteristics of the major types of equipment most commonly used in construction.

For the construction of a large range and is characterized by the number of used mechanization. Therefore,it is construction machinery andEquipment is one of the key factors contributing to the reduction of workcosts, increase productivity, and thus increase the profitability of the industry as a whole.   

                                                                       

Typically, construction equipment is used to perform essentially repetitive operations, and can be broadly classified according to two basic functions: (1) operators such as cranes, graders, etc. which stay within the confines of the construction site, and (2) haulers such as dump trucks, ready mixed concrete truck, etc. which transport materials to and from the site. In both cases, the cycle of a piece of equipment is a sequence of tasks which is repeated to produce a unit of output. For example, the sequence of tasks for a crane might be to fit and install a wall panel (or a package of eight wall panels) on the side of a building; similarly, the sequence of tasks of a ready mixed concrete truck might be to load, haul and unload two cubic yards (or one truck load) of fresh concrete. In order to increase job-site productivity, it is beneficial to select equipment with proper characteristics and a size most suitable for the work conditions at a construction site. In excavation for building construction, for examples, factors that could affect the selection of excavators include:

  • 1.     Size of the job: Larger volumes of excavation will require larger excavators, or smaller excavators in greater number.
  • 2.     Activity time constraints: Shortage of time for excavation may force contractors to increase the size or numbers of equipment for activities related to excavation.
  • 3.     Availability of equipment: Productivity of excavation activities will diminish if the equipment used to perform them is available but not the most adequate.
  • 4.     Cost of transportation of equipment: This cost depends on the size of the job, the distance of transportation, and the means of transportation.
  • 5.     Type of excavation: Principal types of excavation in building projects are cut and/or fill, excavation massive, and excavation for the elements of foundation. The most adequate equipment to perform one of these activities is not the most adequate to perform the others.
  • 6.     Soil characteristics: The type and condition of the soil is important when choosing the most adequate equipment since each piece of equipment has different outputs for different soils. Moreover, one excavation pit could have different soils at different stratums.
  • 7.     Geometric characteristics of elements to be excavated: Functional characteristics of different types of equipment makes such considerations necessary.
  • 8.     Space constraints: The performance of equipment is influenced by the spatial limitations for the movement of excavators.
  • 9.     Characteristics of haul units: The size of an excavator will depend on the haul units if there is a constraint on the size and/or number of these units.
  • 10.  Location of dumping areas: The distance between the construction site and dumping areas could be relevant not only for selecting the type and number of haulers, but also the type of excavators.
  • 11.  Weather and temperature: Rain, snow and severe temperature conditions affect the job-site productivity of labor and equipment.

By comparing various types of machines for excavation, for example, power shovels are generally found to be the most suitable for excavating from a level surface and for attacking an existing digging surface or one created by the power shovel; furthermore, they have the capability of placing the excavated material directly onto the haulers. Another alternative is to use bulldozers for excavation. The choice of the type and size of haulers is based on the consideration that the number of haulers selected must be capable of disposing of the excavated materials expeditiously. Factors which affect this selection include:

  • 1.     Output of excavators: The size and characteristics of the excavators selected will determine the output volume excavated per day.
  • 2.     Distance to dump site: Sometimes part of the excavated materials may be piled up in a corner at the job-site for use as backfill.
  • 3.     Probable average speed: The average speed of the haulers to and from the dumping site will determine the cycle time for each hauling trip.
  • 4.     Volume of excavated materials: The volume of excavated materials including the part to be piled up should be hauled away as soon as possible.
  • 5.     Spatial and weight constraints: The size and weight of the haulers must be feasible at the job site and over the route from the construction site to the dumping area.

Dump trucks are usually used as haulers for excavated materials as they can move freely with relatively high speeds on city streets as well as on highways. The cycle capacity C of a piece of equipment is defined as the number of output units per cycle of operation under standard work conditions. The capacity is a function of the output units used in the measurement as well as the size of the equipment and the material to be processed. The cycle time T refers to units of time per cycle of operation. The standard production rate R of a piece of construction equipment is defined as the number of output units per unit time. Hence:

                                                                                     

or    

                                                                                                                            

The daily standard production rate P e of an excavator can be obtained by multiplying its standard production rate R e by the number of operating hours H e per day. Thus:

                                                                            

where C e and T e are cycle capacity (in units of volume) and cycle time (in hours) of the excavator respectively. In determining the daily standard production rate of a hauler, it is necessary to determine first the cycle time from the distance D to a dump site and the average speed S of the hauler. Let T t be the travel time for the round trip to the dump site, T o be the loading time and T d be the dumping time. Then the travel time for the round trip is given by:

                                                                                  

The loading time is related to the cycle time of the excavator T e and the relative capacities C h and C e of the hauler and the excavator respectively. In the optimum or standard case:

                                                                               

For a given dumping time T d , the cycle time T h of the hauler is given by:

                                                                           

The daily standard production rate P h of a hauler can be obtained by multiplying its standard production rate R h by the number of operating hours H h per day. Hence:

                                                                           

This expression assumes that haulers begin loading as soon as they return from the dump site.

The number of haulers required is also of interest. Let w denote the swell factor of the soil such that wP e denotes the daily volume of loose excavated materials resulting from the excavation volume P e . Then the approximate number of haulers required to dispose of the excavated materials is given by:

                                                                                  

While the standard production rate of a piece of equipment is based on "standard" or ideal conditions, equipment productivities at job sites are influenced by actual work conditions and a variety of inefficiencies and work stoppages. As one example, various factor adjustments can be used to account in a approximate fashion for actual site conditions. If the conditions that lower the standard production rate are denoted by n factors F 1 , F 2 , ..., F n , each of which is smaller than 1, then the actual equipment productivity R' at the job site can be related to the standard production rate R as follows:

                                                                               

On the other hand, the cycle time T' at the job site will be increased by these factors, reflecting actual work conditions. If only these factors are involved, T' is related to the standard cycle time T as:

                                                                                 

Each of these various adjustment factors must be determined from experience or observation of job sites. For example, a bulk composition factor is derived for bulk excavation in building construction because the standard production rate for general bulk excavation is reduced when an excavator is used to create a ramp to reach the bottom of the bulk and to open up a space in the bulk to accommodate the hauler. In addition to the problem of estimating the various factors, F1, F2 ,.., Fn, it may also be important to account for interactions among the factors and the exact influence of particular site characteristics.

  • - The study shows that the users are facing severe hardships as a result of several issues         connected with the use of construction machinery. The ten most important reasons deemed to be the main causes of user probiems have been identified after a rigorous analysis.
  • -  The machinery currently available in  the construction industry are old, used and belong to various makes and models. As a result, their preventive maintenance and repairs have become complicated.
  • -  It was observed that, mostly, machinery hiring firms do operate as pure hiring firms and hence do not consider satisfying the customers as an important requirement to stay competitive in machinery hiring. The immediate attention of the hiring firms and the associated governing bodies should be drawn to address the identified  problems.
  • - The  following recommendations  can be made to alleviate problems causing this situation. initially, the standardization of machinery (having machines from one make and model for each category) seemed to be a solution to address the availability issue of spare parts and to reduce complications in maintenance. However, it was found that this approach has become a failure due to the supplier taking undue advantage by increasing the prices of machine units and spare parts due to the non competitive situation created.
  • - The machinery should be graded based on their real output and not on the rated output. When machines are hired, the users should be made aware of the real output. A systematic procedure has to be followed by the user as well as the hiring firm in selecting the most appropriate machine in terms of size and type in order to execute the tasks economically.
  • - A user is in contact with the hiring firm regarding a machine, it is beneficial to both parties to make a visit to the site in an effort to study the site condition. As a result, the most appropriate machine for the job and a favourable hire rate can be negotiated. Further, this helps to develop the commitment of the hiring firm to the task and to  make him understand the urgency and the seriousness of the task. The hiring firms need to provide a front office service with a person dedicated to liaise with the clienis from their first visit until the time the machine is handed over and to employ professionally qualified staff in order to provide the best possible solutions in the event of problems.
  • - At the time of delivery, the hiring firm should hand over praper documentation regarding the nature of the required routine maintenance regarding the machine and the firms' maintenance policy. The hiring firm should closely monitor the availability of machines and inform the clients well in advance about impending delays. It is necessary  to initiate an informal forum of the hiring firms and contractors in order to improve their relationships.
  •  - It  is proposed that take the initiative to maintain a data base on the web which carries the details of the machinery availability of contractors (and also existing hiring firms if possible to help contractors). This would not be a difficult task as they have provided updated information about the machinery in their possession at the time of renewing the registration. In  situations where mobilizations of specialized machinery are required it is recommended  to subcontract the job to the hiring firm rather than having the contractor do it with hired machinery. This practice can be observed in the construction of bored piles for, foundations. In situations where construction sites are located in hazardous environment (for eg. costal development works, rock blasting etc.) it is advisable for users to go for their own machinery (purchased old machinery). This helps to avert potential unpleasant situations such as the hiring firm discontinuing the contract after the realization of the hazardous state of the site and the possible damage to the machine.
  • -  Contractors need to have an adequate fleet of machinery to appiy for the relevant grading. This makes contractors ending up owning more machinery than demand permits. Even the major contractors do not have a practice of hiring or disposing of machines even when they are lying idle for long periods. As a resuit, the contractors who need to purchase such machinery miss the opportunity. On the other hand, the draining of foreign exchange in having to import similar machinery by the other firms cannot be avoided. The re,asons for doing this are two fold; firstly, to enable them to apply for higher  grading, owing to  the improved capabilities; secondly, to prevent rival firms taking possession of  machinery, cheaply (particularly who are inclined to undertake earthwork contract themselves). Therefore, the criteria for registration of contractors should be revisited with respect to this aspect and steps need to be taken to promote hiring of idle machinery. Some machinery sold at auctions are bought for their value in scrap metal. Most of the time these machinery have expensive and rare spare parts that are still usable.
  • -  It is recommended that registered hiring firms (or contractors) be given an opportunity to cannibalize spares and components prior to their disposal as scrap metals. This to bring down the maintenance cost of machinery, save foreign exchange and lower the hiring rates. The sellers of used spare parts have a practice of buying used machinery at auctions with the intention of cannibalizing. The piled-up machinery awaiting sale on the road-sides is evidence of the difficulty of the importers in affecting sales of these items.
  • -  It is proposed that a study be carried out on the feasibility of importers leasing out such machinery on term leases to the contractors with a buy-back guarantee at the end of the lease.

Strategic decisions mustit is aimed at improving the structure, quantity and quality-governmental characteristics. Only with this approach will be received maxi-mum effect is so necessary modern construction industry in Russia.It remains clear that this area of construction activity sharplyrequires a system of long-term and medium-term planning at alllevels of government building complex.

 

References:

  • 1. Панкратов Е.П., Панкратов О.Е. Проблемы повышения производственного потенциала предприятий строительного комплекса // Экономика строительства. 2015. № 3 (33). С. 4—17.
  • 2. Тускаева З.Р. Инновационные механизмы эффективного управления технической оснащенностью в строительстве. Новосибирск: ЦРНС.2015. 108 с.
  • 3. Rosefielde, Steven and Daniel Quinn Mills, "Is Construction Technologically Stagnant?", in Lange, Julian E. and Daniel Quinn Mills. The Construction Industry, Lexington Books.1999.83p.
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Comments: 4

Adambaev Murat

Результаты исследований несомненно полезны для строительных компаний для оптимизации их менеджмента и повышения ТЭП. В работе не дана оценка возможной погрешности расчетов. С уважением Мурат Адамбаев.

Simonian Geworg

Глубакоуважамый Руслан! Статья актуальна, прежде всего с точки зрения оптимизации и снижения себестоимости строительных работ. Хочется пожелать успехов в внедрении Ваших идей и предложений. С уважением к.х.н. Г.С.Симонян.

Vladimir Karlov

Уважаемый Руслан. В Вашей статье сделан серьезный анализ по проблемам, касающихся методов и средств планирования и реализации строительных объектов. Я, как не специалист в области строительной индустрии, но понимая важность нововведений в ее области, желаю Вам, как специалисту, внедрить все Ваши планы и предложения по улучшению и совершенствованию всего, что касается строительной области. С уважением, Карлов В.А.

Treschalin Michail Yuriyevich

Уважаемый Руслан! Внимательно изучил Вашу работу. С точки зрения оптимизации управленческой деятельности и снижения себестоимости строительных работ Ваши предложения весьма дельные. Для строительных компаний будет польза от их внедрения. В качестве замечания (на будущее): если даете не свои формулы то нужны ссылки на источники и погрешность расчетов. Кроме того, все таки Ваша статья более относится к экономике и управлению, чем к техническим наукам. Желаю успехов! С уважением М.Ю. Трещалин
Comments: 4

Adambaev Murat

Результаты исследований несомненно полезны для строительных компаний для оптимизации их менеджмента и повышения ТЭП. В работе не дана оценка возможной погрешности расчетов. С уважением Мурат Адамбаев.

Simonian Geworg

Глубакоуважамый Руслан! Статья актуальна, прежде всего с точки зрения оптимизации и снижения себестоимости строительных работ. Хочется пожелать успехов в внедрении Ваших идей и предложений. С уважением к.х.н. Г.С.Симонян.

Vladimir Karlov

Уважаемый Руслан. В Вашей статье сделан серьезный анализ по проблемам, касающихся методов и средств планирования и реализации строительных объектов. Я, как не специалист в области строительной индустрии, но понимая важность нововведений в ее области, желаю Вам, как специалисту, внедрить все Ваши планы и предложения по улучшению и совершенствованию всего, что касается строительной области. С уважением, Карлов В.А.

Treschalin Michail Yuriyevich

Уважаемый Руслан! Внимательно изучил Вашу работу. С точки зрения оптимизации управленческой деятельности и снижения себестоимости строительных работ Ваши предложения весьма дельные. Для строительных компаний будет польза от их внедрения. В качестве замечания (на будущее): если даете не свои формулы то нужны ссылки на источники и погрешность расчетов. Кроме того, все таки Ваша статья более относится к экономике и управлению, чем к техническим наукам. Желаю успехов! С уважением М.Ю. Трещалин
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