水土保持通报2024，Vol.44Issue(3)：74-83,10.DOI:10.13961/j.cnki.stbctb.2024.03.009
喀斯特地区马尾松人工林根系抗拉与抗折的力学特性
Tensile and Flexural Properties of Single Roots of Pinus Massoniana in Karst Regions
摘要
Abstract
[Objective]The tensile and flexion mechanical properties and stress-strain characteristics of roots of Pinus massoniana were studied to enrich the mechanical properties of tree roots,in order to provide a reference for soil stabilization and soil erosion prevention in planting areas of Pinus massoniana.[Methods]The 0-1,1-2,2-3,3-4 and＞4 mm root diameter roots of Pinus massoniana were taken as the research object.STS5000 universal tensile machine was used to conduct single root test to analyze the tensile and flexion mechanical properties and stress-strain characteristics of different root diameter roots of Pinus massoniana.[Results]Both the tensile strength and flexural strength of a single root of Pinus massoniana increased with increasing root diameter in accordance with the polynomial relationship of y=ax3+bx2+cx+d,having respective R2 values of 0.91 and 0.69.Both the tensile strength and flexural strength decreased with the increasing root diameter according to y=ax-b,having respective R2 values of 0.50 and 0.35.The root tensile elongation rate increased with increasing root diameter according to the equation y=ax3+bx2+cx+d(R2=0.17),while the root flexural elongation rate had no significant correlation with increasing root diameter.Both the tensile elastic modulus and flexural elastic modulus of the root system decreased with increasing root diameter according to y=ax3+bx2+cx+d,having respective R2 values of 0.22 and 0.18.The root tensile and flexural stress-strain curves of Pinus massoniana showed four stages:elastic deformation,elastic-plastic deformation,strain hardening,and peripheral(fracture)failure.The tensile stress-strain curve generally showed an"upward convex"shape,while the bending stress-strain curve generally showed a"downward concave"shape.The tensile and flexural fracture stages were divided into peripheral fracture and overall fracture modes,both of which were influenced by the peripheral and vascular tissues and had two types of fracture.[Conclusion]The flexural mechanical properties of the root system of Pinus massoniana with a root diameter of＜3 mm were superior to the tensile mechanical properties,while the tensile mechanical properties of roots with diameters of＞3 mm were superior to the flexural mechanical properties.Planting Pinus massoniana in slope areas can effectively increase soil erosion resistance.关键词
喀斯特地区/抗拉力学特性/抗折力学特性/弹性模量/应力—应变特征Key words
karst area/tensile mechanical properties/flexural mechanical properties/elastic modulus/stress-strain characteristics分类
农业科技引用本文复制引用
张晨,彭语童,张建利,杨涛,古宇航,溥丽华,曹阳,赵卫权..喀斯特地区马尾松人工林根系抗拉与抗折的力学特性[J].水土保持通报,2024,44(3):74-83,10.基金项目
贵州省科技计划项目"FAST周边异质生境生态修复模式研究与示范"(黔科合支撑[2021]一般460号) （黔科合支撑[2021]一般460号）
贵州省科技计划项目(黔科合支撑[2022]一般200号,黔科合支撑[2023]一般151号) （黔科合支撑[2022]一般200号,黔科合支撑[2023]一般151号）
贵州科学院省级科研专项(黔科院科专合字[2023]03号) （黔科院科专合字[2023]03号）
贵州科学院创新产业研究启动基金(黔科院C字[2021]1号) （黔科院C字[2021]1号）
贵州省科学技术基金项目(黔科合基础ZK[2023]一般157),贵州民族大学科研基金项目[(2022)YB13] （黔科合基础ZK[2023]一般157）
