铁道建筑

为明确水泥掺量与压实延迟时间对水泥改良风积沙压实特性和强度特性的影响规律，以陕西榆林西成铁路客运专线风积沙为研究对象，采用水泥作为改良剂，设置4%、6%、8%和10%四个水泥掺量，以及0 min、30 min、60 min、90 min和120 min五个压实延迟时间，通过重型击实试验和无侧限抗压强度试验，研究不同工况下最优含水率、最大干密度和无侧限抗压强度的变化，并建立强度预测模型。结果表明：最优含水率、最大干密度以及无侧限抗压强度均随水泥掺量增加而增大；最优含水率随压实延迟时间增加而逐渐降低，最大干密度和无侧限抗压强度呈现先上升后下降的趋势，均在30 min达到峰值。建立的强度预测模型能较好预测试件强度变化。在本文材料组成及室内密封静置条件下，综合压实效果、强度水平及施工可操作性，建议水泥改良风积沙拌合后宜在30 min左右完成压实；当压实延迟超过60 min时，应采取更严格的施工组织与质量控制措施。

To clarify the influence of cement content and compaction delay time on the compaction characteristics and strength properties of cement-stabilized aeolian sand， aeolian sand from the Yulin section of the Xicheng Railway Passenger Dedicated Line in Shaanxi Province was selected as the research object. Cement was used as the stabilizing agent， with four cement contents of 4%， 6%， 8%， and 10%， and five compaction delay times of 0， 30， 60， 90， and 120 min. Through heavy compaction tests and unconfined compressive strength tests， the variations in optimum moisture content， maximum dry density， and unconfined compressive strength under different conditions were investigated， and a strength prediction model was established. The results show that the optimum moisture content， maximum dry density， and unconfined compressive strength all increase with increasing cement content. The optimum moisture content gradually decreases with increasing compaction delay time， whereas the maximum dry density and unconfined compressive strength first increase and then decrease， both reaching their peak at 30 min. The established strength prediction model can accurately predict the strength variation of the specimens. Under the material composition and laboratory sealed-resting conditions adopted in this study， considering compaction performance， strength level， and construction operability， it is recommended that compaction of cement-stabilized aeolian sand be completed at approximately 30 min after mixing. When the compaction delay exceeds 60 min， stricter construction organization and quality control measures should be adopted.