首页|喀斯特地区马尾松人工林根系抗拉与抗折的力学特性

喀斯特地区马尾松人工林根系抗拉与抗折的力学特性

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  • 国家科技期刊平台
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  • NSTL
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[目的]探究马尾松(Pinus massoniana)根系抗拉、抗折力学特性和应力—应变特征,充实乔木根系力学特性,以期为马尾松种植区固持土壤、防治水土流失提供参考.[方法]以马尾松0～1,1～2,2～3,3～4,＞4 mm根径根系为研究对象,使用STS5000万能拉力机进行单根试验,分析不同根径根系马尾松抗拉与抗折力学特性及应力—应变特征.[结果]马尾松单根抗拉力和单根抗折力随根径增加均符合y=ax3+bx2+cx+d方程,R2分别为0.91,0.69;抗拉强度和抗折强度随根径增加均符合y-ax-b方程,R2分别为0.50,0.35;根系抗拉延伸率、根系抗拉弹性模量和根系抗折弹性模量随根径增加均符合y=ax3+bx2+cx+d方程,R2分别为0.17,0.22,0.18;根系抗折延伸率与根系径级无明显相关性;马尾松根系抗拉与抗折"应力—应变"曲线表现出弹性变形、弹塑性变形、应变硬化及断裂破坏4个阶段,抗拉"应力—应变"曲线和抗折"应力—应变"曲线在弹塑性变形阶段有不同的变化趋势;抗拉与抗折断裂阶段有周皮断裂与整体断裂两种断裂模式,两种断裂模式受根系周皮与维管组织影响均有两种断裂类型.[结论]马尾松＜3 mm根径根系抗折力学性能优于抗拉力学性能,＞3 mm根系根径抗拉力学性能优于抗折力学性能.马尾松种植于坡面等地区可以有效增强土壤的抗蚀能力.
Tensile and Flexural Properties of Single Roots of Pinus Massoniana in Karst Regions
[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.

karst areatensile mechanical propertiesflexural mechanical propertieselastic modulusstress-strain characteristics

张晨、彭语童、张建利、杨涛、古宇航、溥丽华、曹阳、赵卫权

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贵州民族大学生态环境工程学院,贵州贵阳 550025

贵州省山地资源研究所,贵州贵阳 550001

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

贵州省科技计划项目贵州省科技计划项目贵州省科技计划项目贵州科学院省级科研专项贵州科学院创新产业研究启动基金贵州省科学技术基金项目贵州民族大学科研基金项目

黔科合支撑[2021]一般460号黔科合支撑[2022]一般200号黔科合支撑[2023]一般151号黔科院科专合字[2023]03号黔科院C字[2021]1号黔科合基础ZK[2023]一般1572022YB13

2024

10.13961/j.cnki.stbctb.2024.03.009

水土保持通报
中国科学院水利部水土保持研究所 水利部水土保持监测中心

水土保持通报

CSTPCD北大核心
影响因子：0.658
ISSN：1000-288X
年,卷(期)：2024.44(3)
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