一、前言 作者在文[4]至文[7]内,对埋地长输管道的热胀内力进行过近似分析,给出一系列近似计算公式,这些公式的限制性是要求直管段比较长。在城市热力管网中,有些管路包含特短的直管段,如“Z”形管路及“Ω”形管路等。这些管路已超出作者所给公式的使用范围。 I. INTRODUCTION In the texts [4] to [7], the author has carried out an approximate analysis on the thermal expansion internal forces of buried long-distance pipelines, and provided a series of approximate calculation formulas. The limitation of these formulas is that straight pipe lengths are required to be relatively long. In urban heat pipe networks, some of the pipelines contain very short straight pipe sections such as “Z” shaped pipes and “Ω” shaped pipes. These pipes are beyond the scope of the formula given by the author.