页岩填料在肯尼亚蒙内铁路中的适用性研究

Study on Applicability of Shale Filler for Mombasa-Nairobi Railway in Kenya

为验证肯尼亚蒙内铁路工程挖方段页岩作为陆域填料的适用性，对不同深度的页岩进行界限含水率、自由膨胀率、崩解性和软化的试验研究，确定页岩是否具有作为填料的稳定性。结果表明：①上层0.0～3.0 m深度内页岩含有一定量亲水性矿物，具有膨胀性，不适合作为陆域填料使用，下层3.0～23.5 m深度内属弱风化和微风化页岩，破碎后不具有膨胀性；②下层3.0～23.5 m内页岩具有一定的崩解性，随着干湿循环次数的增加，页岩将会发生崩解，但崩解产物颗粒级配趋于稳定，崩解后小于0.075 mm的细颗粒含量大于20%；③对下层3.0～23.5 m内页岩进行CBR试验，试样在浸水状态下14天后的CBR值大于6%，满足作为陆域填料的要求。研究结果验证了蒙内铁路3.0～23.5 m深度内页岩作为陆域填料的适用性。

To verify applicability of shale as the land filler in the excavation section of Mombasa-Nairobi Railway, Kenya, the tests of water ratio limit, free swelling ratio, disintegration and softness on the shale in different depth were carried out to confirm whether the shale has the stability as the filler. The result shows that, ①the shale lying at the depth of 0.0～3.0 m in the upper layer contains a certain amount of hydrophilic mineral, thus has expansibility and is not applicable to be taken as land filler; the weak and slightly weathered shale lying at the depth of 3.0～23.5 m in the lower layer will not has expansibility after breakage; ②the shale lying at the depth of 3.0～23.5 m in the lower layer has certain disintegration, and it will disintegrate with the number of dry-wet cycles, however, the particle size distribution of disintegration product tends to be stable with the content of fine grain （smaller than 0.075 mm） more than 20% after disintegration; ③in relation to the CBR test on the shale lying at the depth of 3.0～23.5 m in the lower layer, the sample in soaking state after 14 days has the CBR value more than 6%, which meets the requirement of land filler. The study result verifies that the shale at the depth of 3.0～23.5 m along Mombasa-Nairobi Railway is applicable to be land filler.