Civil Engineering Reference
In-Depth Information
(1) a cobbled area or pavement
(2) set directly on this the (dressed) stone structure of a gate tower
(3) surmounted by the remains of the stone structure of another gate tower of
identical design.
Stone
founda-
tions
Interpretation of this sequence has given rise to head on debate. Stratigraphic
archaeology asserts here an original gate tower set directly on the rubble paving
(i.e. without foundations) followed by a (later period) rebuilding of the gate on the
original lines. h is has been countered by the structural interpretation of a stone
gate house with strong foundations of (dressed) stone beneath the upstanding
walls. h ese foundations are carried down to a rubble mat or pad, the interstices
being i lled with rammed earth (h e Monumental City Gate in Palestine and its
foundations,
ZA
74, 1984, pp. 267-89).
In general, however, the utility of rubble stone footings to the majority of mud
brick walls must have rested on considerations other than the load they imparted
to the ground on which they stood. Such considerations include to provide a level
bed for the convenient setting of upstanding masonry; to resist mechanical damage
prevalent at or immediately above ground level; to resist erosion from e.g. stand-
ing or running water at or immediately above ground level; to prevent deleterious
ef ects on upstanding masonry by “rising damp”, i.e. to function as a damp proof
course (DPC). In this connection it is relevent to observe that although the setting
of courses of rubble at the base of mud brick walls became normal practise, it was
not completely exclusive. Excavation reports note than on occasions brick walls
(both mud brick and burnt brick) were set directly on or into the natural foun-
dations (as will be discussed in the following chapter). h ere is also the revealing
circumstance where foundations for mud brick walls are also of mud brick (i.e.
set below ground level) but above these brick foundations at ground level are two
courses of rubble. Here these rubble footings can not be invested with any stati-
cal functions, but are clearly intended to serve as a D.P.C. etc. as noted above (cf
Naumann, p. 56, i g 30).
In view of the marginal relevence of statical considerations it is rather surprising
how general in the ancient world were rubble footings to mud walls. It is perhaps
only in Southern Mesopotamia that excavation reports indicate that they were
ot en dispensed with and mud bricks set directly into the soil.
Perhaps the i rst building style where the distribution of loads onto natural
foundations became of signii cance was the Pharaonic stone masonry of Old
Kingdom Egypt—i.e. about the middle of the third millenium BC. It is out of
place to discuss this matter in the present context of “mixed construction”, since
whatever the virtue of foundations in Pharaonic masonry, the construction was
an all stone one and thus by dei nition the foundations were of stone. h e ancient
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