Calculation of jacking force by new ATV A-161

Abstract

The development of new production techniques in pipe jacking were the inducement for the improvements of the ATV A-161 (2008). In parallel a new version of the ATV A-125 (2007) came out including the calculation of steerable and non-steerable pipe jacking. The new concept of partial safety factors was also a reason for the revision of the ATV A-161 (2008). One of the modifications and additional topics in the new ATV A-161 (2008) are new materials. The new ATV A-161 (2008) deals also with thermosetting materials like fibre reinforced plastics, and thermoplastics. It is planned that all codes of the ATV will use the same material parameters. Furthermore the standard design loads which occur by using technologies of steerable and non-steerable pipe jacking which are given in ATV A-125 (2007) are described in detail. The theory of silo (diminishment of vertical earth pressure because of arching effects) is used and soil density and consistency are taken into account by the parameters of soil mechanics K (earth pressure coefficient), δ (wall friction angle) and c (cohesion). The new ATV A-161 (2008) gives limiting values for the ratio of wall thickness to radius and includes the calculation of curves and angular deviation due to open loop control, planned bending and angular deviation from production tolerances. The pressure transmitting elements are taken into account. In addition the proofs of stability in axial and longitudinal direction are simplified. For anisotropic materials the effective stresses are verified. The design tables for steel pipes are dropped and for certain boundary conditions the proof of dynamic fatigue for steel pipes can be omitted. The term of this paper is to show the calculation of the forces in longitudinal direction (allowable jacking force) for compression closure pipe connections from new ATV A-161. The structural analysis in axial direction is not performed in this article.