针对预应力混凝土轨道梁线形精度控制难度大，全钢结构轨道梁运营噪声振动等问题，研发了新型群钉连接装配式钢-混凝土组合轨道梁，下部钢梁和上部混凝土板分开预制，通过群钉装配形成组合梁。按1:3几何缩尺比，制作了试验梁模型，对装配前后的钢梁、组合梁固有频率、荷载-挠度曲线、截面高度-应变曲线进行了有限元计算和实测试验，并与界面无滑移钢-混凝土组合等效刚度理论结果进行了对比，获取了不同工况下的刚度调整系数，并验证了其准确性和适用性。研究结果表明：实测荷载-刚度调整系数曲线呈非线性；随试验荷载的增大，刚度调整系数先增大后减小；钢混组合截面不完全符合平截面假定，大幅荷载下混凝土板非线性特性更为明显；基于刚度调整系数对理论值和有限元计算值分别进行修正，得到群钉连接组合梁频率与实测值的误差为 2.2%~4.0%，应力误差为 8.0%~23.8%，在实际工程中，采用该系数可指导并简化该类结构的计算和设计。
In view of the difficulty in precisely controlling the pre-stressed concrete track beam and the operation noise and vibration of all steel structure track beam，a new type of assembled steel-concrete composite track beam connected by group nails was developed. The steel beam and concrete slab were prefabricated separately and installed by group nails. The experimental model of test beam was made according to 1:3 geometric scale. The natural frequency，load deflection curve and section height strain curve of steel beam and composite beam before and after assembly were calculated by finite element method and measured by lab testing. The results were compared with the theoretical results of equivalent stiffness of steel-concrete composite without interface slip，so as to obtain the stiffness adjustment coefficient under different working conditions and verify its accuracy and applicability. The results show that：the measured load stiffness adjustment coefficient curve exhibits nonlinear behavior with the increase of the test load，the stiffness adjustment coefficient first increases and then decreases； the steel-concrete composite section does not fully conform to the assumption of plane section，and the nonlinear characteristics of concrete slab under large load is more obvious；based on the stiffness adjustment coefficient，the theoretical value and the finite element calculation value were modified respectively，and the error between the frequency and the measured value is between 2.2 % and 4.0 % ，and the stress error between 8.0 % and 23.8 % . The calculation and design of this kind of structure can be guided and simplified by using the stiffness adjustment coefficient in practical engineering.
ZHOU Shuai, YU Peng, NIE Jian-guo, et al. Study on stiffness adjustment coefficient of assembled composite track beam connected by group nails[J]. Journal of Transport Science and Engineering,2022,38(1):1-7.