Combining EPS geofoam with geocell to reduce buried pipe loads and trench surface rutting

Abstract

This paper reports full scale experiments, under simulated heavy traffic, of geocell and EPS (expanded polystyrene) geofoam block inclusions to mitigate the pressure on, and deformation of, shallow buried, high density polyethylene (HDPE) flexible pipes while limiting surface settlement of the backfilled trench. Geocell of two pocket sizes and EPS of different widths and thickness are used. Soil surface settlement, pipe deformation and transferred pressure onto the pipe are evaluated under repeated loading. The results show that using EPS may sometimes lead to larger surface settlements but can alleviate pressure onto the pipe and, consequentially, result in lower pipe deformations. This benefit is enhanced by the use of geocell reinforcement which not only significantly opposes any EPS-induced increase in soil surface settlement, but further reduces the pressure on the pipe and its deformation to within allowable limits. For example, by using EPS geofoam with width 0.3 times, and thickness 1.5 times, pipe diameter simultaneously with geocell reinforcement with a pocket size 110×110 mm 2 soil surface settlement, pipe deformation and transferred pressure around a shallow pipe were respectively, 0.60, 0.52 and 0.46 times those obtained in the fully unreinforced buried pipe system. This would represent a desirable and allowable arrangement.

The Role of Expanded Polystyrene and Geocell in Enhancing the Behavior of Buried HDPE Pipes under Trench Loading Using Numerical Analyses

“…EPS blocks with a nominal density of 30 kg/m 3 were implemented in the experimental test. It should be mentioned that the optimum width value according to some researchers is 1.5D [3,13,22].…”

Limit State and Creep Behaviour of High-Density Polyethylene Geocell

“…The cell walls, junctions and the infills integrate into a thick engineered mattress of enhanced rigidity which as a system increases resilience of ground. The advantages have promoted deployment of geocell in a wide range of applications, e.g., foundations and embankments [1][2][3], earth retentions [4], utility pipeline overlying [5], railways sub-tracks [6,7], plate anchors [8], river banks [9] and vibration isolation beds [10].…”

Application of expanded polystyrene (eps) geofoam for the mitigation of dynamic vibrations and distress of civil infrastructure

“…Στη διεθνή βιβλιογραφία δεν έχουν καταγραφεί πειραματικά δεδομένα ή μετρήσεις πεδίου σχετιζόμενα με την απόκριση υπόγειων αγωγών στις δονήσεις που προκαλούνται από τη διέλευση HST. Ωστόσο, υπάρχει μια σειρά πειραματικών δεδομένων που προσομοιώνουν την απόκριση των υπόγειων αγωγών λόγω φορτίων οδικής κυκλοφορίας (Tafreshi et al, 2020, Khalaj et al, 2020…”

“…________________________ (Kouroussis and Verlinden, 2013)); (b) Thalys bogies dimensions (adopted by (Degrande and Schillemans, 2001)). ____________________________________ (Tafreshi et al, 2020)). _______________________________________________________________ 183…”

“…Recently, Tafreshi et al (2020) presented a series of full-scale tests on underground pipelines subjected to traffic-induced loading and examined the reinforcement of the pipelines by implementing EPS geofoam and geocell as backfill layers. According to this study, the use of EPS blocks with height equal to 0.3D and width 1.5D (where D is the pipe diameter) over the pipeline is proposed as the most practical solution.…”