福建典型崩壁土壤硬度特征及其影响因素

Soil hardness characteristics of the collapsing walls of collapsing hillsand its influencing factors in Fujian Province

土壤硬度影响崩岗土壤的稳定性,为探究崩壁土壤的硬度特征及其影响因素,以福建省4个典型花岗岩崩岗发生区(诏安县、安溪县、长汀县、邵武市)的崩壁剖面为研究对象,采用TYD-1型硬度计在野外原位测定土壤硬度,比较不同区域崩壁剖面土壤硬度的差异,研究土壤硬度随剖面深度的变化特征,探究土壤硬度与土壤性质的关系。结果表明,随着土层加深,安溪县、长汀县及邵武市崩壁的土壤硬度整体呈降低的趋势,而诏安县崩壁的土壤硬度则呈先减小后增大的趋势;崩壁土壤硬度的平均值大小为诏安县(24.11 MPa)>长汀县(22.15 MPa)>安溪县(19.83 MPa)>邵武市(14.74 MPa)。影响诏安县崩壁土壤硬度的主要因子为游离氧化铝含量,影响安溪县和邵武市崩壁土壤硬度的主要因子为游离氧化铝和黏粒含量,影响长汀县崩壁土壤硬度的主要因子为土壤有机质和游离氧化铝含量。游离氧化铝是影响4个典型花岗岩崩岗发生区崩壁土壤硬度的共同主要因素,可作为表征研究区域崩岗土壤硬度特征的优选因子。

Soil hardness affects the soil stability of collapsing hills.To clarify the characteristics of soil hardness of the collapsing walls in collapsing hills and its influencing factors,the profile of the collapsing walls of four typical granite collapsing hill areas in Fujian Province(Zhao’an County,Anxi County,Changting County,and Shaowu City)were studied.A TYD-1 type durometer was used to measure soil hardness in situ in the field.The differences in soil hardness in the different regions were compared,the variation of soil hardness with the depth of collapsing walls was studied,and the relationship between soil hardness and soil properties was explored.With increasing profile depth,the overall trend of soil hardness in the Anxi,Changting,and Shaowu sites decreased,whereas the soil hardness in Zhao’an initially increased and then decreased.The average soil hardness ranked as Zhao’an County(24.11 MPa)>Changting County(22.15 MPa)>Anxi County(19.83 MPa)>Shaowu City(14.74 MPa).Soil hardness of the collapsing walls was primarily affected by the content of free alumina in Zhao’an County,contents of free alumina and clay in Anxi County and Shaowu City,and contents of organic matter and free alumina in Changting County.Overall,free alumina was the primary factor affecting the soil hardness of collapsing walls.Therefore,it can be used as the optimum factor to characterize soil hardness of collapsing walls in the study area.