Modern Road Construction and Maintenance Equipment has a very important role in transportation construction cause of the rapid development. With the development of road transport, increase the speed, load surge in traffic, selection of supporting the building of roads and equipment to support proposed new and higher requirements. Therefore, the traditional way of operation and simple maintenance have been completely unable to meet the requirements of road construction and maintenance, support for building the highway's construction and operation must be mechanized, and highlight the very important and very urgent.
Rational use of modern scientific matching highway road building and maintenance machinery and equipment, not only to a department and construction engineering firm economic and technological strength and overall image, but with the quality, schedule and overall economic efficiency are closely related. The election was legitimate, will have a multiplier effect, on the contrary, will make the business suffered huge economic losses, even to the entire department incalculable bad (negative) impact on society. Therefore, the applicability of scientific and rational, economy and reliability of machinery and equipment were Coefficients, optimize the mix, supporting analysis is necessary. To minimize the negative impact brought about because of some unfavorable factors. Strive to reduce costs and avoid device configuration surplus, low capacity utilization and unnecessary costs.
1 Road Machinery optional configuration coefficient
Now on Bridge Engineering Company (two companies) how to buy machinery and equipment and priority allocation lists two sets of coefficients quantitative formula.
1.1 Equipment Series preferably Coefficients formula
a) Equipment price coefficient A1
And equipment at cost in the $ 80,000 to take 0.50; 8 to 15 million take 0.40; 15 to 25 million take O.3 (and so on).
b) affect the quality of road construction coefficient A2
Has a decisive influence take 0.50; general effect of taking 0.25; 0.10 takes less affected
c) equipment utilization coefficient A3
Equipment every day to take 0.50; commonly take O. 25; not commonly used to take 0.10.
d) factors have an impact on the bid A4
Divided into three levels according to the degree of influence, taking 0.50 IMPACT large, medium impact is 0.25, less affected by taking 0.1O. No need to vote for the winning projects available A4 represents versatility of its equipment. According to the job content and scope of work is divided into good, bad, third-class.
e) equipment series preferred coefficient A5
A = Al + A2 + A3 + A4
A value of the portfolio, the more priority to the selection. Try to avoid the election A small value, generally require A> 1.
1.2 Specifications preferred the same numerical formula
The purchase of the same specification product, according to the manufacturer of factors, advanced technology and equipment level, service, household angle evaluation and so on.
In addition, the importance of the case but also on the quality of road maintenance column a correlation coefficient, are designated as mandatory (0.50), need (0.30), general (0.20) and unimportant (0). Other aspects of the case can be set to an engineering operation coefficient values, choose values for future reference. On the coefficients of the above table, determine the size of the device corresponds to the value, and calculate the same product specifications preferably factor X (X = X1 + X2 + X3). We recommend X> 0 when considering the selection. X value, the more priority to the selection.
2 road construction machinery and engineering relationship between volume and configuration (sets)
Construction machinery ideal operating state is to make it an actual operating state with the theoretical running close to each other the possibility of waiting for work then mechanically minimum, Taiwan class fee mechanical waiting close to each other the least, or its TAIPAN comprehensive utilization rate close to the maximum . Construction machinery to cut and fill party, for example, there are two ways to run the system in its mechanical settings.
a) wait for each other to cope with the loss of mechanical TAIPAN cost C 'principle of a minimum configuration. Through different combinations of mechanical, take C 'group that the smallest combination machine configuration. The formula is: C = ΣCiri
Where, ri is the number of i-th machine (i = 1,2,3,4,5), representing excavators, dump trucks, bulldozers, light and heavy rollers); Ci is the i-th machine TAIPAN fees; C 'for a group of machines per shift fees.
b) to the comprehensive utilization of K highest mechanical configuration principles. Through different combinations of mechanical, whichever is the highest K that combination machine configuration. The formula is K = 1-
Derivation and Evolution of the above formula will not repeat here. Evaluation can constitute embankment excavation machinery operation of mechanized construction system, both from the mathematical point of view or from an economic point of view have been demonstrated practice.
2.2 Road Machinery configuration examples
2.2.1 roadbed construction machine
A city highway construction company in Guangxi Guilin-Liuzhou expressway construction in charge of the construction segment filled with rain all the way side, filling earth source from the construction site 3km. Due to construction constraints, we decided to divide two groups from both ends of the construction section construction began filling (two mechanical configurations are the same).
The company's existing machinery as follows: 1.6m3 shovel three; T-54 bulldozer 2; 12t dump truck 30; YZ-12/15 roller 4; T-120 bulldozer three; YZ-6 / 8t roller Taiwan. Among them, the dump truck loaded a car earth take four spade, about 3mm, unloading a car soils need 1.2min.
According to the usual situation in the machinery used in the construction team, were taken K values of various mechanical, calculate the time required for each step of various machinery t and other data. Develop different configuration options, and seek each index and working condition. Since bulldozer excavator, dump truck downtime spent very little work, can not be considered; Similarly, light and heavy rollers make bulldozers, light roller interruption time spent working or may not be considered. After computing demonstration (specifically calculus too kind a little), the mechanical configuration Regardless of which method the foregoing, all with excavator: Dump Truck: T-120 bulldozer: light roller: heavy roller = 1.11 (or 10): 1 : 1: 1 is most reasonable. The actual configuration is consistent with this, the excavator 1, dump truck 10, T-120 bulldozer Taiwan, 2Y-6/8 and 3Y-12/15 and 1 roller table.
2.2.2 asphalt pavement construction mechanical repetition
Construction of Asphalt Pavement System (AMPRS, see photo) ideal job status is: When shaking and shaking machine made good a car material, there is another car just to arrive at the shaking and machine; when the paver needs into When the material, there is a car immediately before the arrival of the paver and unloading; mixed material by paver, light and heavy roller immediately be compacted separately.
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