陕南土坎梯田田坎强度试验研究  

Experimental Study on Strength of Terraced Field Ridge in Southern Shaanxi Province

作　　者：杨娟[1] 李光录[1,2] 魏舟[2] 张腾[2] 李柏桥 付玉[1] 

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]西北农林科技大学资源环境学院,陕西杨凌712100

出　　处：《水土保持研究》2016年第1期360-363,共4页Research of Soil and Water Conservation

基　　金：水利部科技推广计划项目"PP织物袋在陕南地区坡耕地治理中的应用与推广"(TG1308);陕西省水保局重点科技示范"PP织物袋梯田筑坎技术的试验与推广"(20101003)

摘　　要：以陕南土坎梯田田坎为研究对象,通过室内常规三轴剪切试验,对当地梯田田坎的变形和抗剪强度规律进行了研究,分析了田坎土体的应力—应变关系及抗剪强度特性,探究了田坎产生破坏的形式及其产生这种破坏的原因。结果显示:所采土样洋县的为膨胀土,黑山无膨胀性或较弱膨胀性;土样的强度变形关系在较高围压下呈硬化型,随着围压升高结构破坏程度升高,应变强化程度增强,低围压下则呈现出弱软化特性;在土层120cm范围内的田坎土样,其抗剪强度参数沿深度分布无明显规律性,抗剪强度参数对含水率变化敏感,分析认为由于含水率不同致使土层之间存在的抗剪强度差异可能会导致田坎失稳。Terraced field ridge in southern Shaanxi was selected as the study site.A study on strength characteristics of local terraced field ridge was carried out.The stress-strain relationship and shear strength characteristics of ridge soil were analyzed,and the failure mode and cause of retaining wall of terraced field ridge were explored.The results showed that soil samples of Yang County were expansive soil,while soil samples taken from Heishan were not expansive or weak expansion.Strength-deformation relationship of soil samples presented a hardening type at high confining pressure,structure failure and strain hardening level enhanced with the increase of confining pressure,while a weak softening characteristic was observed under low confining pressure.The distribution of shear strength parameters had no obvious regularity within 120 cm depth of soil layer,and they were sensitive to changes in moisture,maybe due to the different moisture contents resulting in differences for shear strength between different soils,which may lead to the instability of ridge.

关 键 词：梯田田坎 应力—应变 粘聚力 内摩擦角 

分 类 号：S281[农业科学—农业水土工程]