The structural design of culverts requires a reliable estimate of the earth pressures which will come to bear on the structure during and after construction of the embankment. The actual bearing pressure at a given time and under various conditions of differential settlement may be greater or less than the deadload of the fill or embankment over the structure. This report describes the instrumentation and construction of three box culverts designed by the imperfect trench method. A total of 42 Carlson earth pressure cells were installed in conjunction with strain gages and settlement measuring devices, including inverted settlement plates and mercury settlement gages. Measurements made during the first few months indicate the imperfect trench has considerably reduced the overburden loads bearing on the structures.

Report Date


Report Number

No. 386

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The contents of this report reflect the views of the author who is responsible for the facts and the accuracy of the data presented. The contents do not necessarily reflect the official views or policies of the Kentucky Bureau of Highways. This report does not constitute a standard, specification, or regulation.