CAJ | 학술논문

为定量评价植物根系固土的时间效应，以岳武高速公路岳西第一标段公路边坡为对象，应用自制的直剪仪对素土及植物生长期61、95、125 d的根土复合体抗剪强度进行现场测定和物理模型预测。试验表明，（1）植物不同生长期根系均能显著增加边坡浅层土壤抗剪强度，增强值与植物生长时间成正相关。其中生长期125 d的根系土壤抗剪强度的提高幅度最大，增加值为5.21 kPa。（2）土体剪切破坏过程中，根系可以有效改善坡面抵抗变形性能。素土试样在位移量为18 mm左右即达到抗剪强度峰值，根土复合体这一数值为19~40 mm；且根土复合体的残余剪切强度平均为素土的2.68倍。（3）通过对比野外实测值与 Wu 模型计算值，Wu 模型高估了根系对土壤抗剪强度的增强作用，相关学者对此提出的折减系数0.4和0.56仍不能与实测值相符，通过计算引入修正系数0.47，模型预测值的精确度最大提高了16.72%，有利于更准确地评估植物根系的边坡稳定作用。
위정량평개식물근계고토적시간효응，이악무고속공로악서제일표단공로변파위대상，응용자제적직전의대소토급식물생장기61、95、125 d적근토복합체항전강도진행현장측정화물리모형예측。시험표명，（1）식물불동생장기근계균능현저증가변파천층토양항전강도，증강치여식물생장시간성정상관。기중생장기125 d적근계토양항전강도적제고폭도최대，증가치위5.21 kPa。（2）토체전절파배과정중，근계가이유효개선파면저항변형성능。소토시양재위이량위18 mm좌우즉체도항전강도봉치，근토복합체저일수치위19~40 mm；차근토복합체적잔여전절강도평균위소토적2.68배。（3）통과대비야외실측치여 Wu 모형계산치，Wu 모형고고료근계대토양항전강도적증강작용，상관학자대차제출적절감계수0.4화0.56잉불능여실측치상부，통과계산인입수정계수0.47，모형예측치적정학도최대제고료16.72%，유리우경준학지평고식물근계적변파은정작용。
With the slope of the first section at Yuexi part of Yuexi-Wuhan Expressway as the research object, the home-made direct shear apparatus was used to conduct in-situ measurement of the anti-shearing strength of plain soil and root-soil composite under the growing periods of 61, 95 and 125 days respectively, at the same time, physical model prediction has also been done, and in this way, quantitative evaluation of the time effects of soil reinforcement by the plant root system. The test shows that, (1) Under different growing periods, the plant root systems could all significantly increase the anti-shearing strength slope topsoil, and the enhancement presented a positive correlation with the growth time of plants. Among them, the root system with a growing period of 120 days had the biggest increase in its anti-shearing strength, with an enhancement of 5.21 kPa. (2) During the shear failure process of soil mass, the root system can effectively improve the performance of resistance to deformation of slope surface. The plain soil sample reached the peak value of shear strength with a displacement of around 18 mm, and for the root-soil composite, this number was 19~40 mm; in addition, the average residual shear strength of root-soil composite is 2.68 times of that of plain soil. (3) By comparing the field measured value with the value calculated with Wu Model, Wu Model overestimated the increase of soil’s shear strength by the root systems. For this issue, related scholars have proposed a reduction factor of 0.4 or 0.56, but it still fails to be consistent with the measured value. Through calculation, a correction factor of 0.47 was introduced, and the accuracy of model prediction has increased by 6.92%, which can help more accurately evaluate the slope stabilization effects by the plant root system.