【摘要】 为探索新型平底密封垫的防水性能，对三元乙丙橡胶平底密封垫进行了数值计算，使用万能试验机进行了压缩试验，制作了混凝土管片试块，进行了足尺防水试验，设计并进行了不同张开量下三元乙丙橡胶密封垫压缩热氧老化试验，并使用阿伦尼乌斯方程预测了密封垫的长期防水性能。研究结果表明：错台分别为0、3、5 mm时密封垫拼装所需的闭合压力分别为24.85、21.87、24.59 kN/m,平底面设计有效减小了密封垫闭合所需的拼装力；不同错台下的闭合压力接近，说明取消柱脚结构减小了错台对密封垫压缩性能的影响；在管片张开3 mm与错台5 mm的最不利工况下，平底密封垫的防水能力达到了0.8 MPa,满足短期设计防水要求的0.7 MPa;混凝土试具试验得到的极限防水能力小于钢制试具，混凝土的粗糙表面降低了密封垫的防水能力，平底密封垫与混凝土之间的界面可能成为潜在的防水薄弱环节；将密封垫底面纳入渗水路径考虑后，大部分工况下试验与数值模拟得到的耐水压差在80 kPa以内，数值模拟方法可靠；与传统带柱脚结构的密封垫不同，取消柱脚结构后底面不再产生应力集中，其防水性能可能小于密封垫顶面；平底密封垫在管片张开0、3 mm时，常温下老化系数分别为0.45和0.72,老化性能优于传统密封垫与圆柱体试件；密封垫受到的压力越大，性能衰减越快，且对温度变化更敏感。更多还原

【Abstract】 To investigate the waterproofing performance of a new type of flat-bottomed ethylene propylene diene monomer(EPDM) gasket, numerical simulations were conducted, compression tests were performed with a universal testing machine, concrete segment test blocks were fabricated for full-scale waterproofing tests, and compressed thermal-oxidative aging tests were designed and carried out under different joint openings. Additionally, the long-term waterproofing performance of the gaskets was predicted using the Arrhenius equation. The research results indicate that when the joint offset is 0, 3 and 5 mm, the closure pressure required for assembling the gasket is 24.85, 21.87, and 24.59 kN/m, respectively. The flat-bottomed design effectively reduces the assembly force required for gasket closure. The similarity in the closure pressure under different offset conditions indicates that the removal of the column base structure reduces the impact of joint offset on the compression performance of gasket. Under the most unfavorable condition of 3 mm joint opening and 5 mm offset, the flat-bottomed gasket achieves a waterproofing capacity of 0.8 MPa, meeting the short-term design waterproofing requirement of 0.7 MPa. The ultimate waterproofing capacity obtained from the test using concrete specimens is lower than that using steel specimens. The rough concrete surface reduces the waterproofing performance and may become a potential weak point for waterproofing. After considering the gasket bottom surface into in the seepage path, the maximum waterproofing pressures obtained through the simulation closely match the test results, with most deviations within 80 kPa, verifying the reliability of the numerical simulation method. Unlike traditional gaskets with column base structures, the removal of the column base eliminates stress concentration at the bottom surface, potentially resulting in lower waterproofing performance at the bottom than the top. Under the joint openings of 0 and 3 mm, the aging coefficients of flat-bottomed gaskets at room temperature are 0.45 and 0.72, respectively, indicating better aging resistance compared to traditional gaskets and cylindrical specimens. The higher the compression force applied to the gasket, the faster the performance of gaskets degradation, and the more sensitive it becomes to temperature change. 3 tabs, 15 figs, 32 refs.更多还原