In order to explore the stability of test square during archaeological excavation for prehistoric earthen sites in Hangzhou, a modeled test square with 2. 3 min depth, inplane dimensions of 5 min width by 5 m in length, and an archaeological column in the middle was excavated by means of a top-down excavation technique. To investigate the stability performance of the modeled test square and the associated effect on the adjacent area, a real-time comprehensive instrumentation program was conducted during the excavation. Field observations included ground settlements, lateral displacement, pore pressure and underground water level. Monitoring data indicates that the ground settlement induced by dewatering and unloading action basically decreases with the increase of the distance away from the pit edge, and the lateral displacements at four sides showa nonlinear variation along the depth. The maximum value is far below the acceptable value regulated by the related standard,which validates the stability of the modeled test square during excavation. Variations of pore pressure and water level suggest that long-term stability should be paid more attention due to the slowconsolidation of soft soil. Meanwhile, it is proved that the step shape of the wall can resist lateral displacement more effectively than the vertical shape of wall. This case study provides insights into the real archaeological excavation in Hangzhou, in particular Liangzhu prehistoric earthen sites.
基于室内物理模型试验和原位锚固试验,对基于高模数硅酸钾溶液-（粉煤灰＋粉土）（PS-（F＋C））浆液的木锚杆锚固系统在夯土介质中进行了拉拔测试与杆体-浆体界面应变监测,研究了该锚固系统的锚固性能与破坏模式、杆体-浆体界面剪应力分布与传递特征。结果表明：该锚固系统室内试验极限锚固力（24～38 k N）远大于现场试验值（2.5～8 k N）;锚固系统具有低弹性强塑性特征,表现出极强的延性;在荷载进程中杆体-浆体界面的应力分布与传递特征具有多峰值分布、高值往往出现在锚固末端、压应力出现等特征,表明该锚固系统兼有拉力型和压力型全长黏结性锚固系统的特点;该系统适合于夯筑土遗址锚固,与遗址具有良好的物理力学兼容性。
表面严重风化是中国西北干旱地区土遗址的主要病害之一。目前解决防风化问题的主要方法是通过研制的防风化加固材料进行工程加固和修复,然而防风化加固材料的研制尚无法满足实际工程的要求。系统研究了不同浓度SH滴渗夯土试样表面渗透半径和渗透速率的分布变化规律,及渗透加固后试样波速和崩解性的变化。试验结果表明,单孔最优注浆量为30~40 m L,此时滴渗时间约为300 min,最终表面渗透半径为3~4 cm。渗透后试样波速升高,抗崩解性能明显提高,以1.0%SH渗透后最为明显。
