马强, 刘岩, 崔强,等.冻融循环作用下含裂隙砂岩强度衰减规律及受荷破裂模式[J].河南理工大学学报（自然科学版）,2026,45(4):140-149.

MA Q, LIU Y, CUI Q,et al.Strength degradation and load-induced failure modes of fractured sandstone under freeze-thaw cycles[J].Journal of Henan Polytechnic University(Natural Science) ,2026,45(4):140-149.

冻融循环作用下含裂隙砂岩强度衰减规律及受荷破裂模式

马强1, 刘岩1, 崔强2, 刘然1

1.国网辽宁省电力有限公司 经济技术研究院，辽宁 沈阳  110027;2.国网电力工程研究院有限公司，北京  102401

摘要: 目的为明晰裂隙砂岩在冻融-围压耦合环境下的力学响应，开展冻融循环与围压条件对裂隙砂岩力学性质及破坏机制的影响研究。 方法 以灰砂岩为研究对象，制备完整、单裂隙和交叉裂隙试样，分别经历0，30，60，90次冻融循环。在单轴及5，10 MPa围压条件下开展压缩试验，获取应力-应变曲线并提取闭合应力、起裂应力和峰值应力等参数。结合裂纹分布和破坏形态，对比不同试样在冻融-围压条件下的力学演化特征。  结果 随着冻融次数增加，3类试样的特征应力均下降，整体刚度减弱。完整试样初期损伤明显，后期趋于稳定；单裂隙试样表现为初期快速扩展、后期缓慢发展；交叉裂隙试样因裂隙相互作用，损伤最为复杂。低围压下裂纹类型多样、破坏复杂，高围压下裂纹模式由剪切向剪切-拉伸复合转变。冻融作用加剧了交叉点应力集中效应，单轴条件下破坏更趋向拉伸或解体，三轴条件下低围压表现为拉-剪复合。  结论冻融循环与围压共同决定裂隙砂岩的力学演化，冻融作用显著削弱强度并促进裂纹贯通，围压一定程度上延缓劣化并抑制拉伸裂纹。与完整试样相比，交叉裂隙试样峰值强度和特征应力的衰减幅度更大，其裂隙更易产生多向扩展并形成贯通网络，进而放大了裂隙岩石对冻融损伤与荷载作用的敏感性。研究成果可为寒区隧道施工、边坡稳定性评价及灾害防控提供理论参考。

关键词:冻融循环;裂隙砂岩;破裂模式;围压效应

doi:10.16186/j.cnki.1673-9787.2025100001

基金项目:国家自然科学基金资助项目（52279116）；国家电网公司科技项目（GCB11202403350）

收稿日期:2025/09/30

修回日期:2025/12/23

出版日期:2026/06/17

Strength degradation and load-induced failure modes of fractured sandstone under freeze-thaw cycles

Ma Qiang1, Liu Yan1, Cui Qiang2, Liu Ran1

1.Economic and Technological Research Institute， State Grid Liaoning Electric Power Co.， Ltd.， Shenyang  110027， Liaoning， China;2.State Grid Electric Power Engineering Research Institute Co.， Ltd.， Beijing  102401， China

Abstract: Objectives To clarify the mechanical response of fractured sandstone under coupled freeze-thaw cycling and confining pressure conditions， the effects of freeze-thaw cycles and confining pressure on its mechanical properties and failure mechanisms were investigated.  Methods Gray sandstone was selected as the research material. Intact，  single-fractured， and cross-fractured specimens were prepared and subjected to 0， 30，  60， and 90 freeze-thaw cycles. Uniaxial compression tests and triaxial compression tests  under confining pressures of 5 MPa and 10 MPa were conducted.. Stress-strain curves were obtained， and characteristic stresses including crack closure stress， crack initiation stress， and peak stress were extracted. Combined with analyses fracture distribution and failure patterns， the mechanical evolution of different specimens under freeze-thaw and confining pressure coupling was systematically investigated. Results With increasing freeze-thaw cycles， the characteristic stresses of all specimen types decreased， and the overall stiffness was reduced. Intact specimens exhibited significant early-stage damage followed by a gradual stabilization. Single-fractured specimens showed rapid crack propagation in the initial stage and slower development thereafter. Cross-fractured specimens exhibited the most complex damage evolution due to interactions among fractures. Under low confining pressure， multiple crack types and complex failure patterns were observed. Under high confining pressure， the failure mode gradually transitioned from shear-dominated failure to shear-tensile composite failure. Freeze-thaw cycling intensified stress concentration at fracture intersections. Under uniaxial loading， failure tended to be tensile-dominated or disintegrative， while under triaxial conditions with low confining pressure， shear-tensile composite failure was dominant. Conclusions Freeze-thaw cycling and confining pressure jointly govern the mechanical evolution of fractured sandstone. Freeze-thaw cycling significantly weakens rock strength and promotes crack coalescence， while confining pressure partially suppresses deterioration and inhibits tensile cracking. Compared with intact specimens， cross-fractured specimens exhibit greater reductions in peak strength and characteristic stresses. Their fractures tend to propagate in multiple directions and form interconnected fracture networks， thereby enhancing the sensitivity of fractured sandstone to freez-thaw damage and mechanical loading. These results provide theoretical support for tunnel construction， slope stability evaluation， and disaster prevention in cold-regions engineering.

Key words:freeze-thaw cycle;fractured sandstone;failure mode;confining pressure effect