洞桩法施工存在群洞效应，极易引起地表塌陷，为了达到安全施工、减小地表沉降的目的，利用MatDEM离散元软件，对洞桩法施工过程进行模拟。对地层微观力学参数进行训练时，考虑了土体的变形潜在机理和土体的亚稳态微观结构，总结了多导洞施工下围岩压力的变化规律。研究成果表明：采用“先上后下、先边后中”的施工顺序时，地表沉降较小；采用“先中后边”时，先挖的中间导洞会使其1.5倍洞宽处发生滑移面分层；采用“先边后中”时，先挖的边洞会产生土供对内侧土体产生竖向支撑作用，降低后挖中洞所产生的地表沉降。上导洞施工时，拱顶、拱腰处的围岩压力呈现增大趋势。下导洞施工导致上导洞拱顶和内侧拱腰处出现应力集中现象。72.65%的地表沉降发生在下导洞施工阶段，采用错距施工能明显缓解土体扰动。

The construction of the pile-beam-arch-method(PBA method) exhibits a cluster-tunnel effect, which readily induces surface subsidence. To achieve safe construction and minimize surface settlement, the MatDEM discrete element software was employed to simulate the construction process of the PBA method. The potential deformation mechanism and metastable microstructure of soil were considered in the training of formation micromechanics parameters, and the variation rule of surrounding rock pressure under multi-guide tunnel construction was summarized. The research findings indicate that when adopting a construction sequence of "top-to-bottom and sides-to-center," surface settlement is relatively small. When using the "center-to-sides" approach, the initially excavated central pilot tunnel leads to the formation of slip planes at 1.5 times the tunnel width. Conversely, with the "sides-to-center" method, the initially excavated side tunnels provide vertical support to the inner soil, reducing the surface settlement caused by the subsequent excavation of the central tunnel. During the construction of the upper pilot tunnels, the surrounding rock pressure at the vault and arch waist exhibits an increasing trend. The construction of the lower pilot tunnels results in stress concentration at the vault and inner arch waist of the upper tunnels. Approximately 72.65% of surface settlement occurs during the construction of the lower pilot tunnels, and the adoption of staggered construction can significantly mitigate soil disturbance.