SHEAR RESISTANCE OF ROOT-PERMEATED HOMOGENEOUS AND STRATIFIED SOIL
SHEAR RESISTANCE OF ROOT-PERMEATED HOMOGENEOUS AND STRATIFIED SOIL
复制标题
DOI：
10.2136/sssaj1977.03615995004100050005x
复制
发表时间：
1977-01-01
影响因子：
2.9
通讯作者：
WALDRON, LJ
中科院分区：
文献类型：
--
作者：
WALDRON, LJ
植物根系对稳定斜坡上的土壤起到机械加固作用。为了测量这种加固作用，对直径25厘米且有根系贯穿的土柱进行了直剪试验。紫花苜蓿（Medicago sativa）、大麦（Hordeum vulgare）和黄松（Pinus ponderosa）的根系都增加了30厘米深处粉质粘壤土均质压实层的抗剪强度。一年生紫花苜蓿的加固效果比移栽16个月后的松树或生长至最大程度的大麦要好得多。大麦在粘壤土中的效果比松树好，但随着深度从15厘米增加到30厘米再到45厘米，其效果减弱。在增加致密砾石 - 砂层（模拟风化岩石）与上覆土壤之间的抗剪强度方面，紫花苜蓿根系比松树或大麦根系更有效，可使抗剪强度提高至休耕土壤的5倍。提出了一个由非刚性根系加固土壤的模型，并给出了因根系加固而使边坡安全系数增加的计算。
Mechanical reinforcement which stabilizes soil on slopes was attributed to plant roots. To measure such reinforcement, direct shear tests were made on 25 cm diameter root-permeated soil columns. Roots of alfalfa (Medicago sativa), barley (Hordeum vulgare) and yellow pine (Pinus ponderosa), each increased the shear resistance of homogeneous and compacted layers of silty clay loam at 30 cm depth. One yr old alfalfa had a much greater reinforcing effect than pine trees 16 mo. after transplanting or barley at its maximum growth. Barley had a greater effect in the clay loam than pine, but its effectiveness decreased as depth increased from 15 to 30 to 45 cm. Alfalfa roots were more effective than either pine or barley roots in increasing the resistance to shearing between a dense gravel-sand layer (simulating weathered rock) and the overlying soil, increasing shearing resistance to as much as 5 times that of fallow soil. A model is presented of soil reinforced by nonrigid roots. Calculations are given of slope safety factor increases from root reinforcement.