Impact Analysis About Deep-rooted Plants On Pipeline Coatings

With the continuous expansion of the scale of China’s pipeline, contradictions betweenthe buried pipelines and plants along them are inevitable. Impact analysis about deep-rootedplants on pipeline anti-corrosion coating has great significance for protecting pipeline security,reducing the burden of pipeline construction and preserving the local economy and resources.This article summarizes the damage of pipeline anti-corrosion coating by plant roots, andanalyzes the failure mechanism of the anti-corrosion coating. The results shows that thedamage of anti-corrosion coating by plant roots has the two following forms, one is theanti-corrosion coating aging and degradation which will produce low-ring compounds andthese compounds can be absorbed by plant roots and aggravate the destruction; the other oneis that the material structure is not compact, some physical properties (such as the needlepenetration) of the material decrease rapidly after the aging or degradation is produced,especially the resistance to external compression puncture, and the material is vulnerable toextrusion and puncture by plant roots.Currently, the destruction by plant roots only occurs in the petroleum asphaltanti-corrosion coating. Although three layer polyethylene (3-PE) anti-corrosion structure iswidely used in pipeline construction, the same destruction case is not found. To further provethe penetration resistant ability of3-PE coating, this article uses the indentation and puncturetest to stimulate the extrusion and puncture of anti-corrosion structure by plant roots andobtains a series of compression resistance data.The indentation test showed that,3-PE anti-corrosion structure can reach stableproportion of indentation depth (PID) under different temperature and pressure, and the PID isnot lager than14%; In the various factors affecting the PID, the influence of the temperatureis the most obvious (the temperature increases, the PID increases significantly) followed bythe pressure(the pressure increases, PID increases slightly), and the hot-melt adhesive nearly has no effect at all; Due to radiation cross-linking effect, there is no direct relationshipbetween the density of the heat-shrinkable belt and its compressive performance.The puncture test shows that extrusion-resistant performance of anti-corrosion materialincreases with the thickness, but has little to do with the density of the material; the burstingstrength of various types of3-PE anti-corrosion structures are all above4MPa with no rigidsupport attached to the bottom of the material, can meet the requirements of generalengineering in bursting strength.Considering the contradiction of pipeline laying and viticulture above in Xin Jiang alongwest second line: this article studies characteristics of local grape root and its influence to themaintenance of pipeline, and draws a conclusion that “neither the grape growing abovedamages the pipeline coating, nor affects the maintenance of pipeline” which has guidingsignificance for engineering application.