The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Voi. XXXVII. Part B5. Beijing 2008 
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The main assumptions for the geostructural model used for the 
analyses of the circuit wall are the following: 
a) the Acropolis circuit wall is a typical case of gravity wall, b) 
the structure of circuit wall simulates very well to that of a 
jointed rock mass while the material of structural blocks are 
typical natural geomaterial (mainly poros stone from the marly 
limestone of Peireas): that simply means that the principles of 
rock mechanics can successfully be applied to the analyses (e.g. 
Medley, 2007), c) with the exception of limited parts of the 
wall (areas with intense planimetric differentiation as comers, 
areas with local peculiarities of backfill and so on) plain strain 
conditions are prevailing, given the great length of the wall 
comparing to its width; that is 2-D analyses can accurately 
simulate the response of the wall at the various loading cases 
examined, d) the initial values of mechanical properties of the 
materials involved in the analyses are coming from the - 
anyway limited- existing laboratory data, the experience of the 
author on materials of similar origin, and the reported literature 
as well; however, further interpretation of material properties 
can originate from study of case histories, through adequate 
back-analyses, e) the seismological data for the analyses are 
based i) on historical recordings, ii) the relevant literature for 
site response (Kramer 1996), iii) on the relevant provisions of 
Greek antiseismic code (EAK, 2000), and, iv) on EC-8 
provisions (Eurocode 8, 1998), taken into account the increased 
importance factor for monuments and the topography effects of 
the surface. 
The following preliminary geostructural analyses concern two 
characteristic cases in the north part of the circuit wall: a) a case 
history from back-analysis of an intensely distorted part of the 
wall, and b) the effect of Arrephorion reburial embankment on 
the stability of the circuit wall in contact. 
A. Preliminary Case Study of rotated/distorted cross-section of 
the North Wall (figures 9 and 10): 
wall base, according to the 3-D model is almost 7cm, and the 
observed rotation is about 1°. In addition, the backfill of the 
wall has a recently deposited extra charge from the arrangement 
of scattered marbles. 
Finally, it is worth noting that, according to archaeological 
evidence, this part of the wall has sustained no visible 
intervention in contrast with neighbouring wall sections. 
The structural back-analysis performed in this case aims at the 
reproduction of the distorted geometry, based on reasonable 
assumptions for both the loading history of the section (soil 
thrust, earthquake etc.) and the calibration of material 
parameters involved. From the analysis results a 6.6cm 
displacement at the top of wall, for acceleration 0.08g. This 
value of assumed acceleration is in agreement with available 
historical evidence in the area of Athens (Papazachos et al, 
2003). 
In the proximity of Arrephorion reburial exists an intensely 
rotated section of the ancient North Wall with about 5m height. 
The horizontal displacement of the wall crest in relation to the 
Figure 9. North part of Acropolis circuit wall. Rotated section 
of the circuit wall. By EJ.Egglezos 
Horizontal 
Displacement 
-6.60e-002 
-6.00e-002 
-5.40e-002 
-4.80e-002 
-4.20e-002 
-3.60e-002 
-3.00e-002 
-2.40e-002 
-1.80e-002 
-1.20e-002 
-6.00e-003 
0.00e+000 
6.00e-003 
Shear 
Tension 
Figure 10. Results from back analysis on distorted North Wall section (exaggerated).