Investigation of the compression-bending capacity evaluation of non-bolted segmental joints

Abstract

This study aims to thoroughly investigate the compression-bending capacity of non-bolted segmental joints (without bolt connection or connect bolt failure) and provide a basis for its compression-bending safety evaluation. First, a theoretical model regarding the compression-bending capacity of non-bolted segmental joints was proposed and verified by full-scale failure tests. Second, a comparison between bolted and non-bolted segmental joints on compression-bending capacity was conducted. Third, the influence of the segment thickness and length of the core pressure zone on the compression-bending capacity of non-bolted joints were analyzed based on the proposed theoretical model and joint parameters from six segmental joints with different segment thicknesses, and the basic characteristic compression-bending capacity curves of non-bolted joints were obtained. Finally, for the convenience of engineering applications, a simplified method for calculating the compression-bending capacity of non-bolted segmental joints was proposed. The results showed that the relative errors between the theoretical model and full-scale tests under positive and negative bending were 3.4% and 6.1%, respectively, indicating that the theoretical model had high calculation accuracy. The influence of the bolt on the compression-bending capacity of a segmental joint increased with increasing segment thickness and decreasing axial force. With the same eccentricity, the compression-bending capacity of the non-bolted segmental joint generally increased with the segment thickness. The compression-bending capacity decreased with increasing length of the core pressure zone under positive bending, while under negative bending the reverse is true. The characteristic compression-bending capacity curve of the non-bolted joint passed through the origin and had three characteristic points. There was a basic compression-bending capacity curve that was independent of the joint parameters for non-bolted joints with different segment thicknesses. The proposed simplified method for calculating the compression-bending capacity of non-bolted joints is highly accurate and easy to use.