Crosspave: a multi-layer elastic analysis programme considering stress-dependent and cross-anisotropic behaviour of unbound aggregate pavement layers

This manuscript describes the development of a new pavement analysis programme called CrossPave based on the Multi-Layered Elastic Theory (MLET) framework, but capable of accommodating stress-dependent and cross-anisotropic behaviour of unbound pavement layers. Generally, Finite Element (FE) based programmes such as ILLI-PAVE, MICH-PAVE, SENOL, GT-PAVE etc. or general-purpose FE programs with special user-defined material sub-routines have been used to model the stress-dependent nature of unbound materials. However, these FE programme are time consuming and need certain expertise, making them unfavourable for implementation into practice. Few MLET-based programmes such as KENLAYER and Everstress are capable of considering the stress-dependent nature of unbound materials, but fail to accommodate some of the recently developed material models. The newly developed pavement analysis programme, CrossPave, addresses these issues, and incorporates five different non-linear stress-dependent resilient modulus models for unbound materials. Details of the developmental effort are presented in this manuscript, along with results from validation efforts highlighting close agreement between KENLAYER, ILLI-PAVE and GT-PAVE. Critical pavement response parameters for two full-scale pavement sections were calculated using CrossPave, and have been compared against field-measured values. The CrossPave programme has been presented as an enhanced, ready-to-implement programme compared to other MLET-based alternatives.