传统支护设计中，往往因为过高的安全冗余度导致资源浪费和成本增加。针对支护设计中反压土的优化问题，为了提高支护结构的安全性与经济性，并避免不必要的过度防护，从而实现资源的高效利用，以呼和浩特市某密贴地铁车站基坑工程为研究对象，结合现场监测与数值模拟方法，系统分析基坑施工中支护结构对基坑和地铁车站变形控制效果。研究重点关注反压土的高度与长度对基坑变形的影响，并在确保实际施工中钢支撑参数不变的前提下，开展反压土体优化分析。通过对不同反压土参数（如长度和高度）的优化分析发现，反压土的高度与长度对地铁车站的最大水平变形具有显著影响。具体来说，随着反压土的高度和长度的增加，地铁车站的水平变形逐渐减小，反之，变形量显著增大。基于这一结论，提出优化的反压土参数选取方案: 高度大于7 m，长度大于80 m，以确保地铁车站的变形控制在安全范围内，满足工程的安全和经济要求。此外，还探讨了不同施工阶段反压土参数调整的合理性。

In traditional support design, excessive safety redundancy often leads to resource wastage and increased costs. Here, the counteracting soil in support design is optimized to enhance the safety and economy of support structures while avoiding unnecessary overprotection, thereby achieving efficient resource utilization. A case study is conducted on a metro station foundation pit project in Hohhot, China, and the control effect of support structures on the foundation pit deformation during construction is systematically analyzed based on field monitoring data and numerical simulation methods. This study focuses on the effects of the height and length of counteracting soil on the foundation pit deformation. An optimization analysis of the counteracting soil is performed while maintaining consistent steel support parameters. Through optimization analysis of different counteracting soil parameters (such as length and height), it is found that the height and length of counteracting soil substantially influence the maximum horizontal deformation of the metro station. Specifically, the horizontal deformation gradually decreases as the height and length of the counteracting soil increase, and vice versa. Based on these findings, an optimized counteracting soil parameter selection scheme—height and length greater than 7 and 80 m, respectively—is proposed. This scheme maintains the metro station deformation within the safety range, thereby meeting the projects safety and economic requirements. Moreover, the rationality of adjusting the counteracting soil parameters at different construction stages is explored.