经PS加固土遗址水饱和强度及加固效果的环境影响研究

SATURATION STRENGTH OF EARTHEN RUINS REINFORCED BY POTASSIUM SILICATE AND INFLUENCE OF ENVIRONMENTAL FACTORS ON REINFORCEMENT EFFECT

以新疆交河故城遗址土做试样,首先用不同浓度的PS加固,经过一段时间干燥后得到不同初始含水率的试样,然后进行渗透系数测试,之后再进行不固结不排水试验,测量试样的抗剪强度。同时,进行PS加固试样的水稳定变化测试(即水中崩解试验),耐风蚀的风洞模拟试验,冻融破坏对加固强度的影响、温差破坏对力学强度影响及干湿破坏对力学强度影响等试验,研究古丝绸之路特殊环境因素对PS加固土遗址保护效果的影响。结果显示,PS加固对土的饱和渗透系数影响很小,而被3%和7%PS加固后的试样峰值抗剪强度比加固前的分别提高了90%和360%,残余抗剪强度也分别提高了50%和250%。结果说明,PS加固后土遗址仍具有很好的渗透性,但被雨水渗透饱和后,仍具有很明显的加固强度。这就证明PS适用于丝绸之路干旱区古代土遗址的加固保护。

Unconsolidated undrained（UU） shear tests were carried out on PS reinforced loess specimens from the ancient city of Jiaohe. Soil specimens were initially reinforced by different PS solutions and then were subjected to saturation before UU tests. At the same time, PS reinforced specimens were subjected to disintegration test in water, to wind erosion test in wind tunnel, to freeze-thaw test, to temperature fluctuation test, and to humidity variation test; so that the influence of serious environment of the ancient Silk Road on the reinforcement effect is studied. Specimens reinforced by 3%PS and 7%PS show higher peak shear strength by 90% and 360% respectively, as compared with unreinforced specimens. The addition of 3%PS and 7%PS reinforcement also result in higher residual shear strength by about 50% and 250% respectively. These results show that PS reinforcement is still effective when subjects to saturation due to rainfall： so that PS is suitable for conservation of the earthen ruins in arid area of the Silk Road.