梯形渠道衬砌冻胀破坏弹性地基板模型  

Elastic foundation plate model for the frost heave damage of trapezoidal canal lining

作　　者：何鹏飞[1,2,3] 候光亮 董建华 曹海涛[1] 马永斌 He Pengfei;Hou Guangliang;Dong Jianhua;Cao Haitao;Ma Yongbin(School of Science,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学理学院,兰州730050 [2]兰州理工大学甘肃省土木工程防灾减灾重点实验室,兰州730050 [3]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,兰州730050

出　　处：《农业工程学报》2022年第23期91-100,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(42001058,52178335,51778275);冻土工程国家重点实验室开放基金(SKLFSE202116);甘肃省自然科学基金(22JR5RA308);兰州理工大学红柳优秀青年基金。

摘　　要：为探讨开放系统中梯形混凝土衬砌渠道的冻胀问题,根据衬砌板与冻土地基的相互关系,该研究采用Winkler弹性地基板理论建立考虑冻胀力和冻结力作用的衬砌板冻胀破坏力学模型,使用解析法得到了衬砌板变形和内力解,对不同地下水埋深、衬砌板几何参数的影响规律进行了分析。通过与已有现场观测值和计算值进行对比,验证了弹性地基板理论计算结果的正确性。研究结果表明:坡板在非均匀分布的冻胀力作用下,挠度、弯矩和剪力也表现为非均匀分布,挠度最大值在坡顶距坡脚2/3处,弯矩最大值靠近底板位置,拉应力分布与内力分布规律一致。与梁理论相比,板理论计算结果表明衬砌板的挠度和内力沿板宽方向为非均匀分布,挠度和弯矩在自由边界(纵向伸缩缝)处增大,扭矩主要分布在衬砌板的拐角处。切向冻结力对渠道冻胀影响较小,在原渠道工况下,不考虑切向冻结力与考虑最大切向冻结力之间,最大挠度相差0.7 mm。针对不同地下水位的渠道,给出了衬砌板的安全厚度,可为现浇混凝土梯形渠道的抗冻胀设计提供参考和理论依据。Frost heave can seriously damage the trapezoidal concrete-lined canal with an open system in cold regions.In this study,the frost heave failure model of canal lining was established to consider the frost heave force and adfreeze force.The Winkler elastic foundation plate theory was also used to describe the relationship between the canal lining and frozen soil foundation.Specifically,the top of the canal slope and the soil of the channel foundation were frozen together,and the foot of the slope and the bottom plate were set as the mutual hinge constraints.The two ends of the plate at the depth direction were assumed to be simply supported boundaries.The adjacent canal lining joints were mostly filled with soft elastic waterproof materials,particularly for the relatively large deformation.The adjacent canal lining board joints were then assumed to be free boundaries.The analytical solution of the model was obtained to clarify the influence of groundwater depth and geometric parameters of canal lining.A comparison was finally made to verify the field observation and calculation.The results show that the bottom plate was subjected to the uniform force of frost heaving.There was an uneven distribution of the internal force and stress along the height direction of the plate.The stress at the free boundary was also slightly larger than that at other positions.The bending moment and shear force of the slope plate were unevenly distributed,where the maximum deflection was 2/3 from the top to the foot of the slope,and the maximum bending moment was close to the bottom plate.A similar distribution of the stress and internal force was also better consistent with the existing research.The maximum stress occurred at the maximum deflection position.The torque was distributed symmetrically along the center of the canal lining,where the maximum was at four corners.It infers that it was easy to produce a stress concentration at the corners.Compared with the beam theory,the plate theory showed that the deflection and internal forc

关 键 词：渠道 模型 冻胀 衬砌 冻结力 弹性地基板 

分 类 号：TV31[水利工程—水工结构工程] S277[农业科学—农业水土工程]