Much of the infrastructure of modern society is buried below ground. Pipeline, conduits and culverts carry the services on which our economies depend and the strength and resilience of such structures is of vital importance. Larger underground construction is becoming more common in cities and towns, and in defence installations. This book brings t

Flexible and rigid pavements were constructed and tested to obtain data on pavement and soil behavior under large aircraft loadings for use in developing criteria for evaluating and designing airfield pavements subjected to multiple-wheel heavy gear loads (WMHGL). The test sections incorporated instrumentation systems designed to determine the response of the pavement structures to static, dynamic (slowly moving), and vibratory loads and to traffic by full prototype loadings of a 12-wheel assembly (one main gear of a C-5A aircraft), a twin-tandem assembly (one twin-tandem component of the Boeing 747 assembly), and a single wheel. Analysis of static load response data from the flexible pavement instrumentation program resulted in the establishment of maximum elastic deflection and vertical elastic stress versus depth curves. Comparisons showed that the same relationships were true for static and dynamic load tests, as well as for speed tests. The findings for the rigid pavement test section indicated that the Westergaard algorithm can be used for reasonable predictio of pavement response to test loadings. The data from the instrumentation program and the traffic tests were used in the analysis of the flexible and rigid pavement test sections. The analysis resulted in a modification of the basic flexible pavement CBR design method. (Author).