A steel-wire wound reinforced thermoplastic pipe (SWW-RTP) has been widely utilized in many industrial areas, and a soil landslide is an inevitable hazardous extreme condition for the SWW-RTP as it is usually buried underground. It is imperative to study the mechanical failure behavior and the failure criterion of the SWW-RTP under the combination of internal pressure and soil landslide conditions, and this paper is the first study to investigate the topic. In this paper, groups of stress–strain curves of high-density polyethylene (HDPE) and steel wires were obtained by uniaxial tensile tests at different strain rates, with the help of a Digital Image Correlation device (DIC). A rate-dependent constitutive model was employed to represent the mechanical behavior of the HDPE and to help deduce the stress–strain curve of the HDPE under the required strain rate, estimated from the static simplification of the dynamic soil landslide. Afterwards, a finite element model of the SWW-RTP, embedded in a cubic of soil, was established with the software ABAQUS. The SWW-RTP model was composed of HDPE solid elements, embedded with steel-wire truss elements, and the soil was characterized with the extended Drucker–Prager model. A quartic polynomial displacement distribution was applied to the soil model to represent the soil landslide. Then, the mechanical response of the SWW-RTP was analyzed. It was found that the failure criterion of the HDPE yield was more suitable for the pipe subjected to internal pressure and soil landslide conditions, instead of the steel-wire strength failure criterion always used in traditional research on the SWW-RTP. Further, the influence of landslide width, internal pressure and steel-wire number were discussed. The larger the width of the landslide area, the gentler the deformation of the pipeline; this resulted in an increase in the maximum landslide and a decrease in the maximum curvature with the width of the landslide area. The relatively high internal pressure was beneficial to the safety of the SWW-RTP under landslide, because the internal pressure could increase the stiffness of the pipeline. The number of steel wires had a limited influence on the maximum landslide required for the SWW-RTP’s failure. This work can be useful for the design and safe assessment of the SWW-RTP under internal pressure and soil landslide conditions.

A multiple-reinforced steel-plastic composite pipe (MRSPCP) is a new type of composite pipe developed in China recent years. The MRSPCP is composed of high-density polyethylene (HDPE) matrix, steel-wire mesh, and steel strip. It is an improved version of the traditional structural wall pipe, and it is able to carry both external and internal pressures. Nowadays, it has been employed in many projects that require large diameter and high flow media transportation, such as water distribution systems, drainage systems, agricultural irrigation systems. As the MRSPCP is newly developed, its mechanical properties and failure mechanism are not clear, and its design method lacks theoretical basis, so this paper carries out the experimental, theoretical and simulated research to investigate the short-term mechanical properties of the MRSPCP. Firstly, uniaxial tensile tests are carried out to acquire the mechanical properties of the constituents. As the steel wire is curly and it is hard to get the stress-strain relationship directly, an inverse identification method was applied to determine the mechanical parameters of a bilinear model representing the steel-wire mechanical behavior. Moreover, short-term burst tests of the MRSPCP are carried out to assess its mechanical performance and provide data for the verification of the theoretical and simulated research. Secondly, a theoretical model is established to calculate the failure pressure by constructing force equilibrium relationship along the axial and hoop directions of the MRSPCP respectively, based on elastic mechanics. In the end, a finite element model of MRSPCP is established, considering the nonlinear mechanical property of the materials. Both the theoretical and the simulated results agrees well with the burst test result, with the relative error of only −13.18% and −4.41% respectively. As the finite element model not only provides more accurate result, but also it can demonstrate contour plots of different constituents inside the MRSPCP, the model is used to study the effects of the pipe thickness, composite strip winding angle and steel-wire diameter on the mechanical properties of MRSPCP. This study might be a guide for the design and safe application of the MRSPCP and similar composite pipes.