不同注浆材料作用下后压浆桩桩-土界面力学特性分析  

Analysis on mechanical properties of post-grouting pile-soil interface with different grouting materials

作　　者：臧诗齐 戴国亮[1,2] 钱晓楠 Zang Shiqi;Dai Guoliang;Qian Xiaonan(Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education,Southeast University,Nanjing 211189,China;School of Civil Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,南京211189 [2]东南大学土木工程学院,南京211189

出　　处：《东南大学学报（自然科学版）》2023年第3期496-503,共8页Journal of Southeast University：Natural Science Edition

摘　　要：为了研究不同注浆材料对后压浆桩桩-土界面的加固效果,开展了大型界面剪切实验.针对后压浆桩在各类土层中的应用,设置了砂土、风化岩、黏土3种不同土样,以研究不同土层环境下压浆对界面剪切性状的影响.采用双曲线模型及考虑剪切应力软化的剪切力学模型对剪切数据进行拟合,通过荷载传递法对压浆桩和未压浆桩的承载特性进行计算分析.研究结果表明,不同注浆材料作用下桩-土界面力学特性均有所改善.在砂土和风化岩中桩-土界面剪切应力与剪切位移之间的相互关系未受压浆影响;在黏土中,压浆改变了桩-土界面的力学特性,呈现出与未注浆接触面不同的软化现象.算例中桩基压浆前极限承载力为7.936 MN,粉煤灰基地聚合物、粉煤灰-水泥以及纯水泥浆液压浆后的极限承载力分别为13.492、13.647、13.926 MN.To investigate the reinforcement effects of different grouting materials on the post-grouting pile-soil interface,a large-scale interface shear test was carried out.According to the application of post-grouting pile in various soil layers,three different soil samples of sand,weathered rock and clay were set.The influence of grouting on interfacial shear behaviors in different soil layers was studied.The hyperbolic model and the shear model considering stress softening were used to fit the shear test data.The load transfer method was used to calculate and analyze the bearing characteristics of grouting pile and non-grouting pile based on the fitting parameters.The results show that grouting different materials can improve the mechanical properties of the pile-soil interface.In sand and weathered rock,the relationship between the shear stress and the shear strain at pile-soil interface is not affected by grouting.In clay,the mechanical properties of the pile-soil interface are changed by grouting and a softening phenomenon different from that of the contact surface without grouting is observed.In the calculation example,the ultimate bearing capacity of the pile foundation is 7.936 MN,and the ultimate bearing capacity of the grouting-piles with fly ash geopolymer,fly ash cement and Portland cement are 13.492,13.647 and 13.926 MN,respectively.

关 键 词：后压浆灌注桩 注浆材料 直剪实验 桩土界面 荷载传递法 

分 类 号：TU443[建筑科学—岩土工程]