CAJ | 학술논문

在客货共线铁路路基设计中，经常遇到填土高度小于路基基床厚度的低路堤、挖方路堑，现行设计规范规定了基床底层范围内的天然地基静力触探比贯入阻力、天然地基基本承载力两项判定指标，如不满足该两项标准，就应进行换填、改良或加固处理。很多设计者在使用该标准时提出了疑问，本文旨在对此问题进行分析落实。通过计算玉、域级铁路不同设计速度对应的动荷载和轨枕底部应力，采用布辛尼斯克公式算出了基床底层顶面及其以下不同深度处的应力，并根据动强度与静强度的关系确定出了基床底层的基本承载力新标准值，建议设计规范采用该新值后取消静力触探比贯入阻力指标。
재객화공선철로로기설계중，경상우도전토고도소우로기기상후도적저로제、알방로참，현행설계규범규정료기상저층범위내적천연지기정력촉탐비관입조력、천연지기기본승재력량항판정지표，여불만족해량항표준，취응진행환전、개량혹가고처리。흔다설계자재사용해표준시제출료의문，본문지재대차문제진행분석락실。통과계산옥、역급철로불동설계속도대응적동하재화궤침저부응력，채용포신니사극공식산출료기상저층정면급기이하불동심도처적응력，병근거동강도여정강도적관계학정출료기상저층적기본승재력신표준치，건의설계규범채용해신치후취소정력촉탐비관입조력지표。
When designing the subgrade of mixed passenger and freight railway, it is not unusual to face the problem of a low embankment or an excavation cutting in which the filling height is less than the thickness of subgrade bed. Considering this reason, for the natural subsoil within the range of the bottom layer of subgrade bed, there are two evaluation indexes in the current design code: the specific penetration resistance of static sounding, and the basic bearing capacity of natural subsoil;still more, if not meeting the two evaluation indexes, the methods of earth replacement, earth improvement or earth strengthening treatment should be utilized. However, these evaluation indexes were questioned by many designers when using them. The purpose of this paper was to analyze and solve this problem. This paper calculated the dynamic load and the stress at the sleeper bottom corresponding to different design speeds of class I and classIIrailways. And then this paper worked out the stresses at different depths above and below the top surface of bottom layer of subgrade bed by using Boussinesq formula. Finally a new standard value of basic bearing capacity of the bottom layer of subgrade bed was determined in this paper according to the relationship between dynamic strength and static strength. It is suggested that the index about specific penetration resistance of static sounding should be abolished after this new standard value has been adopted in design code.