抗滑桩加固黏土边坡可视化模型试验研究

Study on visualization model test of clay slope reinforced by anti-sliding piles

随着基础设施建设不断推进,边坡安全问题日益凸显。为了更好地研究和实施有效的边坡加固措施,对1个无桩边坡、7个不同桩位和桩长的抗滑桩加固边坡进行可视化模型试验,获取无桩边坡的滑动破坏过程,分析桩位和桩长对边坡潜在滑动面与抗滑能力的影响,并给出选取合理桩位和桩长的建议。试验结果表明:无桩边坡随着堆载增大,土体位移矢量变大,滑动轨迹逐渐形成,最终土体从坡趾处剪出,滑动面呈圆弧状;设置抗滑桩,当L(桩长)为1.0H(坡高)时,桩位从S_(x)(桩中心距坡趾水平距离)为0.4H处移动到1.0H处,边坡的潜在滑动面渐变深,剪出口位于坡趾附近,抗滑桩起到一定的支挡阻滑效果,尤其当桩位S_(x)=0.4H~0.6H时,抗滑桩加固边坡效果更佳;当S_(x)=0.8H时,随着桩长L从0.5H增大到1.25H,边坡的潜在滑动面从浅层向深层移动,抗滑能力提高,但L=0.5H~0.75H时,滑动面绕过桩底,抗滑桩易倾覆,未能起到明显的固坡作用;综合分析边坡土体位移场、桩身位移变化特征和坡顶堆载-竖向位移关系曲线等,建议桩位设于边坡中下部(L=1.0H时,S_(x)=0.4H~0.6H),加固边坡效果好且经济。这可为在边坡上修建邮电、交通和供水等基础设施、临时建筑物及防灾减灾提供技术参考。

With the continuous advancement in infrastructure construction,the issue of slope safety has become increasingly prominent.In order to better study and implement effective slope reinforcement measures,visual model tests were conducted on one un-strengthened slope and seven slopes reinforced by anti-sliding piles with different positions and lengths.The tests aimed to observe the sliding failure process of the un-strengthened slope,analyze the influence of pile positions and lengths on the potential sliding surfaces and the anti-sliding capacity of the slopes,and provide recommendations for selecting reasonable pile positions and lengths.The experimental results show that with the increase in load on the un-strengthened slope,the soil displacement vector become larger,and the sliding trajectory gradually forms.Eventually,the soil shears out from the toe of the slope,and the sliding surface is arc-shaped.When anti-sliding pile is set up,and its L(pile length) is 1.0H(slope height),and the pile position moves from S_x(the horizontal distance from the pile center to the toe of the slope)= 0.4H to 1.0H,the potential sliding surface of the slope becomes deeper,and the shear outlet is located near the toe of the slope.The anti-sliding piles provide a certain degree of support and resistance to sliding,and show particularly enhanced effects on slope reinforcement when S_x=0.4H-0.6H.When S_x=0.8H,with the pile length increase from L=0.5H to 1.25H,the potential sliding surface of the slope shifts from shallow layers to deeper layers,and the anti-sliding capacity is improved.However,when L=0.5H-0.75H,the sliding surface bypasses the bottom of the pile,making the anti-sliding piles prone to overturning and failing to provide a significant anti-sliding effect.Considering the comprehensive analysis of the displacement field of slope soil,the characteristics of pile displacement changes,and the relationship curve diagram between the load and vertical displacement at the slope crest,it is recommended to locate the piles at the middle to lower part of the slope(L=1.0H,S_x=0.4H-0.6H),which provides effective and economical reinforcement on the slope.This study can serve as a technical reference for the construction of infrastructure such as telecommunications,transportation,and water supply on slopes,as well as for temporary buildings and disaster prevention and mitigation.