Mechanical characteristics and design method of interlocking concrete block pavement

In order to improve the sizes and vertical interlocking ability of interlocking concrete block for traditional pavement, the larger-size interlocking concrete block with rabbet joint was developed, and its mechanical characteristics were studied. The finite element model of interlocking concrete block pavement was set up, the load transfer efficiency between interlocking concrete blocks was simulated by using spring element, and the influences of block sizes, load transfer ability, thickness of granular base and subgrade strength on permanent settlement and vertical strain at the top of subgrade were analyzed.The permanent deformation of subgrade was adopted as control index, and the relationship between normative accumulated axle-load acting number and vertical strain at the top of subgrade was established.Computation result shows that based on the same conditions of base and subgrade, when block sizes increase from 30cm×20cm to 50cm×30cm, pavement deflection decreases by 25%-30%, and subgrade strain decreases by 25%-45%.When the elastic coefficient of rabbet joint increases from 102 N·m^-1 to 108 N·m^-1, pavement defection decreases by 50%-55%, and subgrade strain decreases by 65%-75%.So the larger-size block with stronger load transfer ability can greatly improve the mechanical characteristics of pavement.In pavement design, the stain level at the top of subgrade can be determined according to the traffic condition of road, based on which the thickness of base layer and the sizes of interlocking concrete block are reasonably designed so that the stain level meets the requirement.