生物聚合物改良预崩解炭质泥岩水稳性及冲刷试验研究

Experimental study on water stability and scour resistance of biopolymer modified disintegrated carbonaceous mudstone

为提高炭质泥岩边坡坡面水稳性及抗冲刷能力,本文利用瓜尔胶生物聚合物改良表层预崩解炭质泥岩。通过开展不同掺量下瓜尔胶改良预崩解炭质泥岩的无侧限抗压强度试验、渗透试验、持水特征试验、崩解试验及边坡冲刷模型试验,分析瓜尔胶对预崩解炭质泥岩力学性能、持水特征、渗透系数、水稳性及坡面抗冲刷能力的影响,并探讨瓜尔胶改良预崩解炭质泥岩微观机理及生态护坡机理。研究结果表明:瓜尔胶可有效增强预崩解炭质泥岩的力学性能,随着瓜尔胶掺量增加,试样无侧限抗压强度增大,养护8 d后,其增幅可达206%;改良预崩解炭质泥岩的含水率及失水速率均随瓜尔胶掺量增大而逐渐减小;瓜尔胶减小了预崩解炭质泥岩的渗透系数,改良后预崩解炭质泥岩渗透系数仅为改良前的4.30%~42.58%;瓜尔胶掺量越大,改良预崩解炭质泥岩崩解率及最终崩解率越小;随着瓜尔胶掺量增加,坡面冲刷速率明显减小,仅为最初的1.0%~6.9%。由此可见,瓜尔胶可有效提升炭质泥岩边坡表层预崩解炭质泥岩的力学性能、持水特性、水稳性及抗冲刷性能,减小其渗透系数,是一种新型、环保的炭质泥岩边坡表层防护材料。

To improve the water stability and scour resistance of carbonaceous mudstone slopes,the surface disintegrated carbonaceous mudstone(DCM)was modified by using biopolymer guar gum.The effects of guar gum on the mechanical properties,water-holding characteristics,permeability coefficient,water stability and slope scour resistance of DCM were analyzed by unconfined compressive strength test,permeability test,water-holding characteristics test,disintegration test and slope scour model test of guar gum modified DCM under different dosing conditions.The microscopic mechanism and ecological slope protection mechanism of guar gum modified DCM were discussed.The results show that guar gum has effectively enhanced the mechanical properties of DCM,and its unconfined compressive strength(UCS)increases with the increase of guar gum content,and the increase amplitude is up to 206%after 8 d.The water content and water loss rate of modified DCM decrease gradually with the increase of guar gum content.Guar gum reduces the permeability coefficient of DCM,and the permeability coefficient after modification is only 4.30%~42.58%of DCM.The larger the guar content incorporated is,the smaller the disintegration rate and final disintegration rate of modified DCM are.With the increase of guar content,the slope scouring rate decreases significantly to only 1.0%~6.9%of the initial.The guar gum can effectively improve the mechanical properties,water-holding characteristics,water stability and scouring resistance of DCM layer of slope surface,and reduces its permeability coefficient,which is a new and environmentally friendly material for carbonaceous mudstone slope surface protection.