潮湿环境模拟考古土遗址夯筑支顶加固效果评估

Evaluation of the effects of reinforcement on rammed earth in a damp environment in a model archaeological site

为研究潮湿环境土遗址加固效果评估方法,在杭州地区进行现场模拟探方加固实验,并对加固后坑壁的波速、含水率、相对水平位移进行监测,对加固的模拟探方稳定性做出评估,以望通过采用科学定量手段评价土遗址夯筑支顶加固效果,为土遗址夯筑支顶加固效果评估提供参考。试验结果表明:模拟探方坑壁表层含水率随深度的增加而升高,含水率变化量逐渐减小;加固后坑壁土体初始强度随深度的增加而提高,且后期硬化过程也较上部区域快,土体强度随时间在逐渐增加;夯筑后坑壁前四五天位移值逐渐增大,且位移值随深度的增加而升高,后期趋于稳定。研究表明,基于变形监测技术评估夯筑体整体稳定性科学合理,基于表层含水量和波速变化评估夯筑土体强度变化是较好的手段。评估结果可为其他潮湿地区土遗址夯筑加固效果评估方法提供参考。

In order to evaluate the effects of reinforcement of earthen archaeological sites in damp environments,on-site experiments were done to reinforce a simulated archaeological excavation unit in Hangzhou City. The wave velocity,water content,and relative horizontal displacement of a reinforced pit wall after reinforcement were measured. Then the stability of the simulated archaeological excavation unit was evaluated,expecting that of done in a quantitative,scientific way,reference information for assessment of the reinforcement effects could be obtained in other earthen archaeological sites. Experimental results show that the deeper the earth,the higher the water content on the surface of the pit wall; that the initial strength and the hardening process of soil ramming increase as the depth increases; that the strength of ramming soil increases as time goes on; that 4 ~ 5 days after reinforcement,the displacement accelerates; and that the deeper in the body,the bigger the displacement. The research results show that deformation monitoring is a useful scientific method to evaluate the stability of the reinforcement. Surface moisture and wave velocity monitoring are reasonable parameters for measuring the strength of rammed earth.