桩周土体物理力学性质对滑坡抗滑桩桩间距的影响

Influence of Physical and Mechanical Properties of Soil around Piles on Spacing of Anti-slide Piles in Landslide

抗滑桩加固是滑坡防治的主要工程措施之一,桩周土体物理力学性质对桩-土相互作用有较大影响,进而影响抗滑桩桩间距的确定。基于抗滑桩最小桩间距的计算方法,通过解析法分析了桩周土体物理力学性质对土拱强度条件和桩-土相互作用平衡条件的影响,并利用数值模拟方法研究了桩周土体物理力学性质改变后对抗滑桩桩后滑坡推力分布形式的影响;针对部分渣土边坡中土体物理力学性质较差导致抗滑桩桩间距较小的问题,提出了渣土边坡堆积过程中在抗滑桩设桩处周围填筑改良土体的方法来优化抗滑桩的最小桩间距,并对填筑土体类型、填筑范围和填筑深度进行了研究;讨论了桩周土体物理力学性质对抗滑桩最大桩间距的影响,并将其影响结果与桩周土体物理力学性质对抗滑桩最小桩间距的影响结果进行对比,分析了桩周土体物理力学性质对抗滑桩最小和最大两种桩间距影响效果不同的原因。以深圳某渣土边坡为例验证了在桩周填筑改良土体优化抗滑桩最小桩间距的方法,结果表明该方法在不增加施工成本和施工难度的基础上优化了抗滑桩的最小桩间距,可达到节省渣土边坡治理成本的目的。

Reinforcement of anti-slide piles is one of the main engineering measures for landslide prevention and control.The soil around the piles has a great influence on the pile-soil interaction,which in turn affects the pile spacing.Based on the calculation method of the minimum pile spacing of anti-slide piles,this paper applies the analytical method to analyzing the influence of the physical and mechanical properties of the soil around the piles on the equilibrium conditions of pile-soil interaction and the strength of soil arch a the variation of the thrust distribution pattern of landslide behind piles after the soil around the pile is changed by the numerical simulation.To deal with the problem that the poor physical and mechanical properties of some slag slope lead to the small pile spacing,the paper puts forward the method of filling the improved soil around the piles with anti-slide piles in the process of filling the slag slope,and studies the type,filling range and depth of filling soil.Taking a slag slope in Shenzhen as an example,the paper verifies the method of optimizing the minimum pile spacing of the improved soil in the piles around the piles,which can optimize the minimum pile spacing without increasing the construction cost and construction difficulty and save the cost of slag slope treatment.Finally,the paper discusses the influence of the physical and mechanical properties of the soil around the piles on the maximum pile spacing,and compares the impact results with the influence of the surrounding soil on the minimum pile spacing.The paper also analyzes the reasons for the different effects of the physical and mechanical properties of the soil around the piles on the maximum pile spacing and the minimum pile spacing.