评价打桩机的精度对其经济性的影响.docVIP

ECONOMIC EVALUATION OF THE ACCURACY IN THE OPERATION OF PILE DRIVING-MACHINES K. N. Kondyrev, Vo V. Gerasimov, UDC and Io Eo Kalinina UDC 624o155o15o003ol The accuracy in pile driving affects substantially the output of pile-driving machines -with increased accuracy- the machine output drops and the cost of driving the plies increases accordingly. An economic evaluation of the accuracy in the operation of the most widely used pile-driving machines is presented below As shovm in [1], each type of pile-driving machine is characterized by a definite and inherent rela- tion among the accuracy in the pile-driving operation, the subsidiary time spent, and the output. Conse-quently, different types of machines may drive piles at different costs~ according to the required driving accuracy. For determination of all types of costs in pile-driving operations, the writers developed an economic- mathematical model of the pile-driving process, which consists of a set of relations among all the for- mulas and equations linking the operating characteristics of the pile-driving machine and its technical parameters° This model plays the role of instrument for transformation and storage of processed infor- m.ation~ with the aid of which the required relations are formalized, and the optimal parameters of the pile- driving machine are determined for the given optimization criterion -the minimum converted costs. In its general form, the cost of driving piles into soils is a function of several variables, among them the driving accuracy: cpi=f (to .....), (1) in which to is the net pile-driving time, machine-hours; and is a variable quantity which depends on the pile-driving accuracy, The outlays on mechanization of the driving of piles into soils by a set of machines at a construction projects are expresse