Study on the blast mitigation behavior of metakaolin-based foam geopolymer (MKFG) as tunnel cushioning layer against external blasts

IF 5.7 1区工程技术 Q1 ENGINEERING, CIVIL

Thin-Walled Structures Pub Date : 2024-11-26 DOI:10.1016/j.tws.2024.112752

Wenxin Wang , Fangduo Xiao , Hang Zhou , Shikun Chen , Zhen Wang , Yi Liu , Dongming Yan

{"title":"Study on the blast mitigation behavior of metakaolin-based foam geopolymer (MKFG) as tunnel cushioning layer against external blasts","authors":"Wenxin Wang , Fangduo Xiao , Hang Zhou , Shikun Chen , Zhen Wang , Yi Liu , Dongming Yan","doi":"10.1016/j.tws.2024.112752","DOIUrl":null,"url":null,"abstract":"<div><div>In this study, the similarity model contact blast test and numerical simulations were carried out to investigate the protective behavior of tunnels with a metakaolin-based foam geopolymer (MKFG) cushioning layer under blast impacts. In contact blast test, Rock-Foam Geopolymer-Concrete Tunnel (RFGCT) structures with various densities (400, 600 and 800 kg/m<sup>3</sup>) of MKFG were tested against a blast impact of 100 g TNT. In numerical simulations, several parameters covering TNT equivalent as well as density and thickness of cushioning cladding, were comprehensively discussed. Test results show that the attenuation rate of cushioning cladding to the blast wave is enhanced from 34.7 % to 71.0 % with the reduction of the density of MKFG from 800 kg/m<sup>3</sup> to 400 kg/m<sup>3</sup>. Meanwhile, the reflected tensile wave generated by blast wave falls from 1.85 MPa to 0.66 MPa. When the density of MKFG exceeds 600 kg/m<sup>3</sup>, the cladding exists obvious defects in energy absorption at the bottom of mid-span and free end, which gradually disappear as the TNT equivalent and cushioning thickness increases. Increasing thickness of the MKFG-400 can lead to excessive overall displacement of the tunnel lining. Full-size uncertainty analysis shows that at TNT equivalents of 2000 kg, the thickness of MKFG-800 as cushion is recommended to be 2–3 times that of the lining.</div></div>","PeriodicalId":49435,"journal":{"name":"Thin-Walled Structures","volume":"207 ","pages":"Article 112752"},"PeriodicalIF":5.7000,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Thin-Walled Structures","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0263823124011923","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}

引用次数: 0

Abstract

In this study, the similarity model contact blast test and numerical simulations were carried out to investigate the protective behavior of tunnels with a metakaolin-based foam geopolymer (MKFG) cushioning layer under blast impacts. In contact blast test, Rock-Foam Geopolymer-Concrete Tunnel (RFGCT) structures with various densities (400, 600 and 800 kg/m³) of MKFG were tested against a blast impact of 100 g TNT. In numerical simulations, several parameters covering TNT equivalent as well as density and thickness of cushioning cladding, were comprehensively discussed. Test results show that the attenuation rate of cushioning cladding to the blast wave is enhanced from 34.7 % to 71.0 % with the reduction of the density of MKFG from 800 kg/m³ to 400 kg/m³. Meanwhile, the reflected tensile wave generated by blast wave falls from 1.85 MPa to 0.66 MPa. When the density of MKFG exceeds 600 kg/m³, the cladding exists obvious defects in energy absorption at the bottom of mid-span and free end, which gradually disappear as the TNT equivalent and cushioning thickness increases. Increasing thickness of the MKFG-400 can lead to excessive overall displacement of the tunnel lining. Full-size uncertainty analysis shows that at TNT equivalents of 2000 kg, the thickness of MKFG-800 as cushion is recommended to be 2–3 times that of the lining.

查看原文本刊更多论文

求助全文

约1分钟内获得全文求助全文

来源期刊

Thin-Walled Structures 工程技术-工程：土木

CiteScore

9.60

自引率

20.30%

发文量

801

审稿时长

66 days

期刊介绍： Thin-walled structures comprises an important and growing proportion of engineering construction with areas of application becoming increasingly diverse, ranging from aircraft, bridges, ships and oil rigs to storage vessels, industrial buildings and warehouses. Many factors, including cost and weight economy, new materials and processes and the growth of powerful methods of analysis have contributed to this growth, and led to the need for a journal which concentrates specifically on structures in which problems arise due to the thinness of the walls. This field includes cold– formed sections, plate and shell structures, reinforced plastics structures and aluminium structures, and is of importance in many branches of engineering. The primary criterion for consideration of papers in Thin–Walled Structures is that they must be concerned with thin–walled structures or the basic problems inherent in thin–walled structures. Provided this criterion is satisfied no restriction is placed on the type of construction, material or field of application. Papers on theory, experiment, design, etc., are published and it is expected that many papers will contain aspects of all three.