任务精讲：膨胀土围岩课件讲解.pptx

隧道施工技术膨胀土围岩TunnelConstructionTechnologySurroundingRockofExpansiveSoil

膨胀土围岩目录TableofContentsSurroundingRockofExpansiveSoil膨胀土围岩的特性1CharacteristicsofSurroundingRockofExpansiveSoil膨胀土围岩隧道的施工要点2KeyPointsforConstructionofTunnelwithSurroundingRockofExpansiveSoil课程小结4Summary膨胀土隧道的处置措施3TreatmentMeasuresforTunnelinExpansiveSoil

膨胀土是指土中粘土矿物成分主要由亲水性矿物组成，同时具有吸水膨胀软化和失水收缩硬裂两种特性。决定膨胀性的亲水矿物主要是蒙脱石粘土矿物。膨胀土围岩SurroundingRockofExpansiveSoilExpansivesoilreferstosoilinwhichtheclaymineralcompositionismainlycomposedofhydrophilicminerals.

Meanwhile,ithastwocharacteristics:expansionandsofteningafterwaterabsorption,andshrinkageandhardcrackingafterwaterloss.Thehydrophilicmineralsthatdetermineitsexpansibilityaremainlymontmorilloniteclayminerals.

膨胀土围岩SurroundingRockofExpansiveSoil膨胀性围岩SurroundingRockofExpansiveSoilSpecialsurroundingrockmassMudstone,shale,feldspar,mica,serpentiniteandotherrocks.特殊性围岩体泥岩、页岩、长石、云母、蛇纹岩等岩石。

膨胀土围岩SurroundingRockofExpansiveSoil膨胀性围岩SurroundingRockofExpansiveSoilDistributionareaofexpansivesoilYunnan,Guizhou,Sichuan,Guangdong,Guangxi,Shanxi,Shandongandotherprovincesandregions.膨胀土分布面积云、贵、川、两广、山西、山东等省区。现已发现有膨胀土发育的地区达20余个省、市、自治区，遍及西南、西北、东北、长江与黄河中下游及东南沿海地区。Expansivesoilhasbeenfoundinmorethan20provinces,municipalitiesandautonomousregions,coveringthesouthwest,northwest,northeast,middleandlowerreachesoftheYangtzeRiverandtheYellowRiver,andthesoutheastcoastalareas.

随着时间的增长导致围岩失稳，支护、衬砌变形和破坏。或因风化而开裂等现象。使坑道的顶部及两侧向内挤入，底部鼓起。膨胀土围岩SurroundingRockofExpansiveSoilorcrackedduetoweathering.Thetopandbothsidesofthegalleryaresqueezedinward,andthebottombulges.Astimegoeson,thesurroundingrockisunstable,andthesupportandliningaredeformedanddamaged.隧道穿过膨胀性围岩地层，开挖后不久，常常可以看见围岩因开挖而产生变形。Ifthetunnelpassesthroughtheexpansivesurroundingrockstratum,