【作者】 邓江东；

【导师】 罗强；

【作者基本信息】 西南交通大学 ， 道路与铁道工程， 2004， 硕士

【摘要】 基床病害是我国铁路上分布得最广、数量最多的一种路基病害，而且随着列车轴重、运量及运行速度的提高有日趋严重的趋势。对于运营中的铁路病害基床，混凝土夯扩桩和混凝土夯扩桩与土工格室联合作用是高效快捷的加固处理方案，值得推广。 为了分析研究加固方案的效果，结合达成铁路、成都铁路北环线病害路基整治工程，进行了现场测试试验。本次试验主要分三种测试断面：正常断面、混凝土夯扩桩加固断面、混凝土夯扩桩与土工格室联合作用加固断面。为了全面反映基床的应力和变形性能，测试项目主要有长期沉降、动应力、动变形、动速度和加速度等。 从水准观测的数据来看，加固断面的沉降稳定期一般在4个月左右；由于加固断面对基床扰动较深，初期沉降速率较大；10个月后所有加固断面的平均沉降速率均小于10mm／y。试验测得的路基动力学数据均在合理的范围；与车辆相比，机车产生的动力学指标明显要大，成为路基动力学状态的决定性影响因素。加固断面由于轨面平顺性较差等原因，基床的动力学反应较大；但路基的动反应模量K_d、地基系数K₃₀、地基承载力[σ]等数据表明采用的病害基床加固方案能显著提高基床强度、刚度及承载力，达到了加固的要求。 试验结果表明，混凝土夯扩桩和混凝土夯扩桩与土工格室联合作用加固方案均能增加基床的强度和抗变形的能力，具有较理想的加固效果。更多还原

【Abstract】 Subgrade defects are widespread in our country and with the increasing of axle weight and running speed the trend is deteriorating day by day. For the ill subgrade in use, concrete rammed cast-in-situ pile and concrete rammed cast-in-situ pile combined with geocell are swift and high-efficient methods, worth popularizing.Based on renovating the subgrade of dacheng-railway and chengtiebeihuan-railway, this experiment was carried out to analyse the practical effect. Three kinds of test sections were mainly divided: normal sections, sections reinforced by concrete rammed cast-in-situ pile, sections reinforced by concrete rammed cast-in-situ pile combined with geocell. In order to reflect the dynamic properties of subgrade, the experiment items mainly included longtime subsidence, dynamic stress, dynamic displacement, acceleration, dynamic velocity, etc.According to the leveling data, generally 4 months or so is needed for reinforced sections to steady; because the reinforced subgrade is disturbed deeply, at initial stages it subsides rapidly; after 10 months subsidence speed of reinforced sections is lower than 10mm/y. The subgrade" s dynamics data got in the experience are in rational range. Compare with vehicle, the locomotive, which producing dynamics indexes obviously great, becomes the decisive factor of the dynamic state of subgrade. Due to track irregularity, dynamic response of the reinforced subgrade is relatively great; but the dynamic deformation modulus Kd, subgrade coefficient K30, the bearing capacity of foundations [a] etc show that the schemes can improve subgrade" s strength, stiffness and bearing capacity, reaching the project demand.The results have demonstrated that the two schemes of concrete rammed cast-in-situ pile and concrete rammed cast-in-situ pile combined with geocell can improve subgrade’s intensity and capability of resisting deformation, reaching an ideal reinforcement effect.更多还原