土质路基荷载下地基反力试验研究

地基反力σ能够反映荷载作用下地基受力的情况,但其在土质路基特别是高压实度土质路基荷载作用下的研究并不多。本文通过现场及室内离心模型模拟土质路基的填筑及放置过程的试验,对地基反力进行研究。研究表明:高压实度土质路基荷载作用下地基反力呈弧形分布,路基宽度范围内地基反力小于γH值,靠近坡脚的路基边坡区域大于γH值。路基中心处地基反力σc与路基宽高比b/H有很大关系,当路基宽高比b/H较小时,σc与γH值差距较大;当b/H较大时,σc与γH值差距减小;当b/H大于10时,σc基本等于γH值。本文结合试验结果得出考虑b/H影响的路基中心处地基反力σc的计算方法,提出新的地基反力沿路基横断面的计算公式,使路基荷载下地基反力的计算结果更接近实际;结合试验得到路基中心处实测地基反力及地基沉降值,对两种中等压缩性土地基在路基荷载作用下的地基反力与地基沉降的关系进行讨论,得出其相关性较好的地基反力系数,为今后土质路基荷载作用下地基反力系数的应用提供了参考资料。

Experimental Study on Ground Reaction under Loding of Soil Subgrade

Ground reaction(GR) σ reflects the stressed conditions of ground under the action of loading,however,it is seldom referred to when ground is subjected to self-weight loading of soil subgrade,especially highly-compacted soil subgrade.Field tests and indoor centrifugal model simulation were conducted on filling and placement of soil subgrade to study GR.The results show as follows:Under the loading of highly-compacted soil subgrade,GR(σ) is arc-shaped across the subgrade section,the value of GR(σ) is smaller than γH within the width of the subgrade and larger than γH near the foot of the subgrade slope;at the center of the subgrade,GR(σc)is highly related to the width height ratio(b/H) of the subgrade,the difference between GR(σc) and γH is large corresponding to a small b/H,it decreases with increasing of b/H;σc equals γH when b/H exceeds 10;in accordance with test results,the equation of GR(σc) at the center of subgrade and the equation of GR(σ)across the section of the subgrade are set,both taking b/H into account and acquiring results more close to reality;the GR coefficient of good relativity is found through discussion of the relationship of the ground reaction coefficients and settlements of two types of medium-compacted soil subgrade under self-weight loading integrated with the measured GR and ground settlement,at the center of the subgrade.Reference information is provided for further application of GR under loading of soil subgrade.