战国秦时期夯土长城加固强度试验研究

Tentative research on the consolidated Great Wall of Qin Dynasty at the Warring States

对已风化而频临危险的文物进行渗透加固保护以提高土的胶结强度,是国际上普遍认可的科学加固方法。通过室内单轴抗压强度、抗剪强度和渗透试验研究发现,抗压强度随浓度及加固次数增加而提高,材料具有可重复使用性,但加固剂的浓度增加不宜超过7%;φ值随加固剂浓度和加固次数有明显增加趋势,c值有所提高但变化没有明显的规律性;土经固化后的渗透系数略有降低,但变化在同一数量级内,不影响土的渗透性。综合分析试验结果,对于密度为1.3～1.50g·cm-3风化墙面,以浓度5%～7%的PS材料多次加固为宜;密度为1.5～1.7g·cm-3的风化墙面适宜以3%～5%浓度的PS材料多次加固。加固后强度和渗透性满足文物保护特殊要求。

The Great Wall was announced as the first batch of key cultural relic unit under State Protections by State Department in 1961,and was listed as the world cultural heritage by UNESCO in 1987. And these constructions are humankind's precious cultural heritage,and their valuable artistic value is rare worldwide. Through the compression test,the shear strength test and the infiltrate test,the results of test indicate that the compression strength and the shear strength increases with the PS material consistency and the reinforcement times,and that he PS meterials can be multiple application. At the same time,the results show that the 7 % PS materials is the best consistency to consolidating the soil of the Great Wall. In addition,the permeability coefficient of the reinforced sample decreases and the permeability meets the requirements of preservation of cultural relics. By a comprehensive analysis,the 3 %—5 % of PS is suitable for consolidating the wall whose dry density is 1.5—1.7 g·cm-3,but 5 %—7 % of PS is fit for consolidating the wall whose dry density is 1.3—1.50g·cm-3. In sum,the key to protecing ruins is choosing the suitable PS consistency material and consolidation times in order to enhancing penetrability of PS material. So this reinforced method could be effective in protecting the Great Wall of Qin Dinasty in the Warring States in Northwest China.