#Calibrate apsim statistical method manual
#Calibrate apsim statistical method verification

Performance-based specifications - which describe desired levels of fundamental engineering properties that are predictors of performance or.Performance specifications - which directly define the condition of the road, the response of the road to load, and/or the condition of the pavement materials at a given period of time,.Performance specifications may be presented in one of three forms, including (after Chamberlin, 1995): Performance Specification - A specification for key materials and construction quality characteristics that have been demonstrated to correlate significantly with long-term performance of the finished work ( e.g., the pavement shall support 1 million ESALs without developing fatigue cracks or rut depths exceeding 6 mm (0.25 in.)). This form of specification states what property must be achieved, allowing the contractor some liberty to innovate the process to satisfy the intended result ( e.g., a dry density of 95% of the maximum dry density - as determined by AASHTO T99, standard Proctor - shall be obtained for each lift of soil placed on the grade). Result Specification - The result specification is normally shorter and easier to write than the method specification. Method Specification - This form of specification describes in detail the equipment and procedures (process) used to achieve a desired result ( e.g., a compactive effort of 4 passes using a 35-ton sheepsfoot roller - Caterpillar C825 or equivalent - shall be made on each 8-inch lift of loose soil spread on the grade). An example of each type is provided below: The specifications can generally be categorized as method, result, or performance specifications. These documents may contain guideline specifications ( e.g., AASHTO Standard Specifications for Transportation Materials, AASHTO, 2004) modified by the local agency to address local conditions, materials available, construction techniques commonly employed, and their local experience. Most agencies have developed as part of the construction process a set of standards and specifications. There is no good practice other than what is specified in the contract. The specification dictates the quality for the pavement section construction, with the intent of tying the design to the finished product (design intent в‡” performance). The development of the specifications is usually conducted in the pre-construction phase as part of the design. Proper treatment of the subgrade during construction will assure expedient construction of the pavement section, enhance pavement performance over its life, and ensure that the pavement design intent is carried through in the construction phase (Ohio DOT, 2002). It is now up to construction to achieve these requirements. The designer has made assumptions based on the subsurface exploration program as to the support conditions and the field requirements anticipated to meet those support conditions ( i.e., the anticipated adequacy of existing support after grading or modifications required to achieve that support). Fundamental to the pavement construction is the preparation of the pavement foundation ( i.e., the subgrade) to meet the pavement design support requirements. In either case, the engineer typically must make do with the local soils and design for the site conditions encountered. For instance, a new roadway alignment could be conceptualized in a flat topography, requiring little earthwork, or conversely, in a hilly or mountainous topography that requires large cuts - excavation and/or rock blasting - and placement of deep fills. Projects come in all shapes and sizes, each presenting unique challenges. Lastly, a review of monitoring techniques for the finished product is provided, an important consideration with the current move toward performance specifications and warranties. Issues surrounding the preparation of the pavement foundation, focused primarily upon cut and fill soil construction, prepared subgrade, chemically stabilized soils, and unbound engineered aggregate layers (base/subbase) are detailed.

#Calibrate apsim statistical method verification

As such, construction specifications are described, quality control/quality assurance concepts are reviewed, and innovative measures of design verification are provided. The last phase of work required to complete a roadway, the construction phase, is the emphasis of this chapter.

#Calibrate apsim statistical method manual

Thus far, this reference manual has described the processes detailing the pre-construction phase - site characterization and design. Geotechnical Aspects of Pavements Reference Manual Chapter 8.0 Construction And Design Verification For Unbound Pavement Materials 8.1 Introduction