Introduction
1.1 What I study
I reverse engineer archaeological buildings & structures from posthole evidence.
Using traditional architectural technical drawing, CAD, and deductive reasoning to build functionally accurate models.
Working with the complete scaled dataset to identify basic structural components.
I started in 1990 [1] & published online here since 2008. {so they are not all new}
Postholes are the most numerous archaeological features on certain types of sites.
Thus, Theoretical Structural Archaeology represents a set of analytical techniques for understanding certain archaeological data sets.
1.2 What qualifies as a discovery
Insights & discoveries of potential national or international importance.
Completely original & not copied from other scholars or site reports.
Outside of my primary work as a professional archaeologist.
Work done in my own time.
1.3 Wider context of Theoretical Structural Archaeology
My basic methodology has been peer reviewed in the USA. [2]
Theoretical Structural Archaeology is maths & science based where possible.
Models are refined by looking for errors, inconsistency and poor mathematical fit.
To the best of my knowledge I am the only UK archaeologist working on the interpretation of timber built environments.
This was the basis of a PhD at Newcastle, but evidence based archaeology and science proved incompatible with image based post-processualism subjectivism.
1.4 Format - 30 page A4
Brief and concise summary of the insight, idea or discovery.
Details, definitions & Implications - maximum of six.
Summary or example illustration as space permits. {this is a very visual subject}.
To Fit on A4 sheet, ie. 30 Pages {+ this one}, in 3 groups;
Basic structural modelling {from c. 430 lecture / video slides} 1-7
Advanced Structural Models & Case Studies 8 - 22
Archaeology of Hadrian’s Wall { from 3 Videos + 120 lecture slides} 23 -30
2. Basic structural modelling
2.1 Reverse Assembly Truss
The most important concept and the basis of any understanding of post built buildings is the difference between normal and reverse assembly. {sectional view}
A Truss is composed of a rafter pair with a horizontal Tie across the bottom.
This triangle is the basis of the roof as understood; a building is a roofed structure.
Assembly is the detailed order in which the structural components are put together; i.e. foundations first to thatch last.
Normal Assembly; in a building with load bearing walls, the load of the roof is supported on a solid wall or timber frame, the roof truss and its tie sit on top.
Reversed Assembly; in a building where the mass of the roof is supported on posts, it is practical to place the posts directly under the ties.
This arrangement allows for;
Offset posts which simplified jointing
Lightweight wall construction
Still present in Far Eastern tradition, {performance in earthquakes}.
2.2 The Offset Tie
Apparent irregularity in the layout of posthole foundations can be explained as a product of offset jointing, which simplifies construction and allows the rafter pair to be at right angles to the roof plate & ridge.
This single observation explains the ground plan of reverse assembly structures.
It is present in LBK Longhouses, roundhouses, & larger circular buildings {Classs Ei}.[3]
Enables the distinction of structures such as floors from roof supports.
It probably originates in PPNA as it is present at Göbekli Tepe.
2.3 Relationship between postholes & trees
A long tradition of forestry and woodland management has developed a detailed understanding of trees which can be directly related to the remains of archaeological timber structures. Through data contained in species specific yield tables.
DBH is diameter at breast height {4’}, is good approximation for size of the post pipe
The key metric is the height of crown formation {c.⅔ top height }
Larger trunks can be box sectioned
Coppice is method of growing multiple stem on single root system
Yield tables can form the basis of modelling
The general parameters of buildings and structures are in part a product of the local availability of timber .
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2.4 Relationship between trees & buildings
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