AN INVESTIGATION INTO UPHEAVAL BUCKLING OF BURIED PIPELINES .1. EXPERIMENTAL APPARATUS AND SOME OBSERVATIONS

This paper and its companion describe an experimental study of some as pects of the upheaval buckling of buried pipelines by means of a small -scale model apparatus. After a discussion of relevant literature, the experimental apparatus is described in detail: it involves a thin-wal led steel pipe of diameter 6 mm and length 5 m, buried in a bed of art ificial soil. The horizontal and vertical profiles of the pipe are mea sured by an electrical remote-sensing device. Axial load is imparted t o the pipe by a screw arrangement and/or by interior oil pressure; and transverse horizontal loading may be applied through a string and pul ley. The arrangements for assaying the resistance of the soil to trans verse motion of the pipe are described. Results are presented for seve ral tests involving both axial and transverse loading, and cyclic axia l loading. The paper concludes with a short discussion.