ECONOMIC ASPECTS OF VERTICAL SAND DRAINS

THE HIGHWAY ENGINEER HAS A NUMBER OF METHODS TO CONSIDER AS A SOLUTION TO THE PROBLEM OF CROSSING MARSHLAND WITH ROAD CONSTRUCTION. HIS CHOICE OF METHOD WILL DEPEND ON ENGINEERING ASPECTS AND ECONOMIC CONSIDERATIONS. IT IS ASSUMED THAT THE COST OF BRIDGE STRUCTURES WILL GENERALLY EXCEED VARIOUS TYPES OF FILL CONSTRUCTION. HENCE, DISCUSSION IS RESTRICTED TO ECONOMIC CONSIDERATION OF MUD-EXCAVATION, SURCHARGED-MUD, AND SAND-DRAIN METHODS. RELATIONSHIPS ARE DEVELOPED WHICH INDICATE THE CONSTRUCTION COST DIFFERENTIALS INVOLVED IN CONSIDERING MUD EXCAVATION AND THE SAND-DRAIN METHOD. THE PROPER CONSIDERATION OF THE SURCHARGED-MUD METHOD AS A SOLUTION TO THE PROBLEM IS DISCUSSED. SOURCES OF INFORMATION RELATED TO THESE PROBLEMS ARE NUMEROUS AND THE AUTHOR IS CONSCIOUS THAT ECONOMIC STUDIES ARE GIVEN CAREFUL ATTENTION BY ALL HIGHWAY DEPARTMENTS. HOWEVER, WORK TO DATE HAS SHOWN THAT THE ECONOMIC CONSIDERATIONS ARE A FUNCTION OF MANY PARAMETERS, THE EXACT INTERRELATIONSHIPS OF WHICH THE ENGINEER CAN ONLY ESTIMATE. FORMULATION, HOWEVER, PERMITS SOME COMPOUNDING WHICH MAKES THE OTHER PARAMETERS STAND OUT PROMINENTLY. TOTAL COST DIFFERENTIAL INVOLVING COSTS RELATED TO TIME AND MAINTENANCE ARE DISCUSSED. /AUTHOR/