针对在役高速公路深厚软基段出现失稳滑移的问题，提出桩顶带连系梁的微型桩快速处治方法。结合开阳高速公路K3202+577~K3202+640段软基加固抢险实际工程，介绍微型桩和连系梁的加固方案和施工工艺。加固后实测的深层水平位移和路基沉降变形大幅减小，表明该方法可有效处治软基滑移病害。采用Plaxis 3D软件建立深厚软基连系梁微型桩加固变形的数值分析模型，通过与实测值对比分析，验证了模型的合理性；研究了桩间距、桩排距、连系梁布设形式对滑移处治效果的影响，结果表明：水平位移随着桩间距增大而增大，桩间距超过10倍桩径后，土体侧移增大速度明显加快；水平位移随排间距增大会先减小后增大，排间距不宜超过10倍桩径；加设连系梁能减小路基土体侧移和优化微型桩受力，桩顶不同形式连系梁的处治效果排序为：双向交叉连系梁 > 单向交叉连系梁 > 斜向连系梁 > 纵向连系梁。
Aiming at the instability and slip in the deep soft foundation section of in-service highway, a quick treatment method of micropile with coupling beam at pile top is proposed. Combined with the actual project of soft foundation reinforcement in Kaiyang highway from mileage K3202+577 to K3202+640, the reinforcement techniques micropile and coupling beam are introduced. The measured deep horizontal displacement and settlement of soft subgrade are greatly reduced after reinforcement, indicating that this method can effectively mifigate sliding. The numerical analysis model for the deformation of deep soft foundation reinforced by coupling beams and micropiles is established by Plaxis 3D. The rationality of the model is verified by comparison with the field measured data, with influences of spacing, row spacing and form of coupling beam on treatment effect investigated. The results show that the lateral displacement increases with the increase of pile spacing, and when the pile spacing exceeds 10 times pile diameter, the soil lateral displacement increases obviously.The addition of coupling beam can reduce the lateral displacement of subgrade soil and optimize the stress of micropiles. The treatment effect of different types of coupling beams is ranked as follows:bidirectional cross coupling beam, followed by unidirectional cross coupling beam, then oblique coupling beam, while longitudinal coupling beam is the least. The conclusions can provide reference for the optimization design of similar projects.