【摘要】 基于分级加载单轴抗压蠕变试验,研究世界文化遗产云冈石窟9,10,12窟窟前立柱岩体的长期强度,并对其长期承载力学性能进行评价。研究结果表明:(1)云冈石窟9,10,12窟窟前立柱岩体的岩性主要为砂岩,岩性单一,结构面不发育,属整体块状岩体结构类型,工程地质条件良好。(2)立柱岩体中粗粒砂岩的长期强度低于中粒、中细粒砂岩的长期强度。其根本原因在于,中粗粒砂岩的胶结物类型是泥质胶结;其中含有微量的蒙脱石,在长期的风化过程中,与水作用后,易发生淋滤作用和溶蚀作用,次生裂隙相对较发育。(3)高含水量状态下,中粗粒砂岩的长期强度为20.22MPa,比其在低含水量状态下的长期强度降低44.31%。按云冈石窟立柱应力最大值出现在10窟西柱的上部(1.31MPa)计,中粗粒砂岩立柱岩体的安全系数为15.4。因此,9,10,12窟窟前立柱岩体的长期承载力学性能良好。建议尽快修复和搭建窟檐,避免雨水对石窟的冲刷,同时还能调节窟内温度与湿度,减轻风化剥蚀。计算9,10,12窟窟前立柱最大可以承载的窟檐质量,供有关建筑设计和文物保护部门参考。这些研究结果和建议对于云冈石窟的保护具有一定的指导意义。更多还原

【Abstract】 Based on the uniaxial creep experiment with step-loading,the long term strength of pillar rockmass before grottoes No.9,10,20 at the world culture heritage Yungang Grottoes is studied and the long term mechanical properties is also evaluated.The results show that:(1) the pillar rockmass mainly composed of sandstones is with a good geological environment such as a single type of rock and good structure without developed joint.(2) the long term strength of the medium coarse-grained sandstones is lower than that of the medium-grained and medium fine-grained sandstones.The reasons for these are that the medium coarse-grained sandstone is argillaceous cementing and it contains montmorilonites which easily make reactions with water molecules resulting in the rockmass joints relatively developed.and(3) under condition of high moist content,the long term strength of the medium coarse-grained sandstones is about 20.22 MPa dropping 44.31% than that under condition of low moist content,and the safety stability factor of the pillar rockmass is 15.4 if the maximum stress numerical value(1.31 MPa) occurs on the upper of the western pillar of the grotto No.10.It is suggested that the rehabilitating should be implemented as soon as possible for the protection of the grottoes from the rain erosion and weathering.The maximum quality the pillar rockmass can bear can be a reference for related departments of architectural design and relics protection.The study results and suggest possess guiding significance for protecting Yungang Grottoes.更多还原