杨凌地区日光温室土质墙体失效机制分析研究

Failure Mechanism of Earth Walls in Solar Greenhouse in Yangling Area

为了研究杨凌地区日光温室土质墙体发生失效的原因,将其失效形式总结为墙体表面不均匀脱落、墙体发生开裂变形与墙体失稳发生滑移三种类型,对杨凌地区发生失效的日光温室土质墙体取样,对土样进行含水率试验、直剪试验与无侧限抗压试验,并通过设计杨凌地区代表性日光温室进行受力分析并进行验算。经试验测定含水率低于5%时墙体表面较易发生不均匀脱落现象,后墙土坡下部含水率相较于中部与上部高2%左右。验算结果表明在含水率为15%、20%时后墙土坡摩尔-库伦曲线与土样抗剪强度曲线均为相离,当含水率为15%时,后墙土坡中部也有发生剪切破坏的危险;含水率在18%以上时,墙体容易在荷载下发生破坏。土质墙体日光温室发生较多的失效形式为表面不均匀脱落与剪切破坏,通过控制墙体的含水率来防止墙体失效是一种有效的方法,本研究对杨凌地区日光温室土质墙体的建造和使用与对温室内作物生长环境的保护具有一定的指导意义。

This study aims to investigate the failure causes of the earth walls in the solar greenhouse in Yangling area.Three types of failure forms were summarized as uneven shedding of the wall surface,cracking and deformation of the wall,and the wall instability resulting in sliding.Samples were collected from the earth walls in the solar greenhouse in Yangling area,and and various tests such as moisture content,direct shear,and unconfined compression were conducted on the soil samples.Stress analysis and checking calculation were performed based on the design of a representative solar greenhouse in the Yangling area.The test results showed that when the water content was below 5%,the wall surface was prone to uneven shedding.The water content of the lower part of the earth slope on the back wall exhibited a moisture content approximately 2%higher than that of the middle and upper parts.The checking results showed at moisture contents of 15%and 20%,the Mohr-Coulomb curve of the back wall soil slope deviated from the shear strength curve of the soil sample.A risk of shear failure in the middle of the soil slope of the back wall was observed at a moisture content of 15%.When the water content exceeded 18%,the wall was susceptible to damage under load.The failure forms of the earth walls in solar greenhouses were identified as uneven shedding and shear failure.Controlling the water content of the wall proves to be an effective method for preventing wall failure.This study provides valuable guidance for the construction and use of soil walls in solar greenhouses and the preservation of the crop growth environment in the Yangling area.