Continuous pile and column foundations of towers in Siberian towns and ostrogs

Purpose. In the course of archaeological research of Russian ostrogs (wooden fortresses) in Siberia, which belong to the end of the 16th - the first half of the 18th centuries, researchers come across remains of defensive fortifications, interpretation of which is rather complicated. Such remains include traces of continuous pile and column foundations of ostrog towers. The objective of this article is to identify all known structures of this type, determine essential ele-ments of their construction and discover the functional purpose of such a foundation. Results. In the course of archаeological research, four towers with continuous pile and column foundation were dis-covered, namely, a south-western tower of Umrevinskii Ostrog, one of Tobolsk towers, a south-eastern tower and a north-western tower of Udinskii Ostrog. Information on discovery of towers with such a foundation in Mangazeya was not confirmed. The existence of such a foundation under the western tower of the Sosnovskii Ostrog remains dis-putable. One of such towers preserved its original foundation in the town of Bel'sk (Irkutsk region) till 1987. Three towers with continuous pile and column foundations were discovered in Krasnoyarskii Ostrog in written sources. Conclusion. It is determined that all towers were located on the slope or next to it, their dimensions were considerably smaller than average ones, while their depth and thickness of logs were equal and met the same parameters of the lath fence walls. Such towers were intended first for reducing a load on unstable grounds on the slopes and next to them at the expense of small sizes of towers and secondly for preventing uneven subsidence of the tower bases, which due to a small perimeter thereof can result in a considerable lurch and subsequent collapse or damage of the structural integrity of the building.