Abstract:

In order to availably protect embedded petroleum pipelines through a slope particularly under seismic actions, a new frame-type stabilizing pile with the pipelines covered is proposed. On the basis of determining the seismic landslide thrust force on the structure by the pseudo-static method，the load section of the structure located above the sliding surface is taken as the plane frame structure which is taken as the plane rigid frame structure with fixed bottom. A super-static plane rigid frame structure model is used to analyze the loading section. The part of the structure below the slip surface called the embedded section is actually two independent piles buried in the stable layer, which can be analyzed using the elastic beam on foundation model under lateral loads on their tops. Thus, a calculation method of internal forces and displacements of the frame-type stabilizing pile is established by combing the two parts. The results of an example show that the deviation between the proposed and the numerical bending moments and shear forces of the front and rear piles as well as the upper and lower beams of the frame-type stabilizing pile is within 20%, and the proposed results are relatively conservative. The influence of horizontal seismic coefficient on the internal forces is obvious. The maximum value of the internal forces increases approximately linearly with the seismic coefficient, while the influence of vertical seismic coefficient is slight. The maximum internal force of the structure is linear positive correlation with soil unit weight and nonlinear negative correlation with cohesion and internal friction angle of soil, respectively. As soil shear strength parameters increase, the internal forces of the front and rear piles together with the upper and lower beams tend to be close, respectively. The maximum internal forces of the two piles and the two beams are nonlinear positive and negative correlation with flexible rigidity of the piles, respectively； But are approximately linear positive and negative correlation with embedded depth of the piles, respectively. The separation between adjacent structures has obvious influence on the structural internal forces, but the row spacing between the two piles in the same structure has slight effect on them.

Key words: petroleum pipelines, slope, frame-type stabilizing pile, plane rigid frame, elastic beam on foundation