塑钢纤维喷射混凝土力学性能及现场试验  

Mechanical Properties of Resemble Steel Fiber Reinforced Shotcrete and Field Test

作　　者：柴荣山 孔二伟 丛凯 倪效学 CHAI Rong-shan;KONG Er-wei;CONG Kai;NI Xiao-xue(Shandong Road&Bridge Construction Group Co.,Ltd.,Ji′nan 250014,China)

机构地区：[1]山东省公路桥梁建设集团有限公司,济南250014

出　　处：《价值工程》2023年第33期153-155,共3页Value Engineering

摘　　要：喷射混凝土广泛应用于隧道工程围岩支护中,是一种有效的初期支护手段。普通喷射混凝土为脆性材料,抗弯拉强度低,在软弱围岩或破碎岩体支护中,喷层易开裂,严重威胁施工安全。为了提高喷射混凝土的支护能力,添加塑钢纤维,增强喷射混凝土韧性。依据纤维力学增强机理,研究不同掺量塑钢纤维对喷射混凝土的抗压、劈裂抗拉和抗弯强度的影响;并开展现场喷射试验,对隧道周边收敛进行监测与分析。结果表明,塑钢纤维存在有最佳掺量,塑钢纤维喷射混凝土具有良好的抗压、抗拉和抗弯能力;在围岩支护中,起到让压卸载作用,喷层中应力分布较均匀,减少喷层开裂,适用于破碎或变形较大的围岩支护中,具有良好的推广应用价值。Sprayed concrete is widely used in tunnel engineering surrounding rock support and is an effective initial support method.Ordinary sprayed concrete is a brittle material with low flexural and tensile strength.In weak or fractured rock mass support,the sprayed layer is prone to cracking,posing a serious threat to construction safety.In order to improve the support capacity of sprayed concrete,plastic steel fibers are added to enhance its toughness.Based on the reinforcement mechanism of fiber mechanics,the effects of different amounts of plastic steel fibers on the compressive,splitting tensile,and flexural strength of sprayed concrete are studied;and on-site spraying tests are conducted to monitor and analyze the convergence around the tunnel.The results indicate that there is an optimal dosage of plastic steel fibers,and plastic steel fiber sprayed concrete has good compressive,tensile,and bending resistance.In surrounding rock support,it plays a role in relieving pressure and unloading.The stress distribution in the spray layer is relatively uniform,reducing the cracking of the spray layer.It is suitable for surrounding rock support with large fragmentation or deformation,and has good promotion and application value.

关 键 词：塑钢纤维 喷射混凝土 隧道工程 围岩支护 让压卸载 

分 类 号：TU528[建筑科学—建筑技术科学]