Using expanded polystyrene geofoam and tire-derived aggregate in different forms to reduce vertical earth pressure on high-filled cut-and-cover tunnels

Al-Arkawazi, Shamil Ahmed Flamarz; Hajiazizi, Mohammad

doi:10.1080/23311916.2022.2138100

Cited by 4 publications

(1 citation statement)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several factors, including the geogrid existence, the form of the TDA, the thickness of the TDA, and the distance between the bottom of the TDA and the top of the HFCCT were studied. It was determined that the factors are having significant effects on the LEP reduction on the HFCCT through the earth pressure reduction mechanisms, where the average LEP on the top of the HFCCT model reduced from 303 kPa to 125 kPa [15] .…”

Section: Introductionmentioning

confidence: 99%

Lateral Earth Pressure Reduction on High-Filled Cut-and-Cover Tunnels Using Expanded Polystyrene Geofoam and Tire-Derived Aggregate

Flamarz,

Hajiazizi

2024

PJBAS

View full text Add to dashboard Cite

Currently, high-filled cut-and-cover tunnels (HFCCTs) are a practical solution for the prospect of reclaiming valuable usable lands with valleys and hilly terrain around the world. As a result of the very high backfill soil amount above the HFCCT producing very huge earth pressure, it is essential to use methods of load reduction methods to reduce the earth loads and pressures on the HFCCT, which will increase the safety by reducing the tunnel designing loads. This study focuses on six load reduction scenarios using expanded polystyrene (EPS) and tire-derived aggregate (TDA) in three different forms. The research includes using EPS geofoam and TDA in arch and combined horizontal and arch formations as methods of LEP reduction on HFCCTs which is the first time these methods have been used as methods of any type of load reduction on HFCCTs. A number of significant factors, including the suggested EPS and TDA forms, the EPS and TDA thickness, and the distance between the bottom of the EPS or the TDA and the top of the HFCCT were studied. The study results determined that a significant LEP reduction on the HFCCTs was achieved, especially with the use of TDA in a horizontal form. Also, model verification was made by comparison between the calculated and estimated LEP values on the HFCCT study model using the Rankine equation, Rankine modified equation, and Abaqus CAE 2019 software. The calculated and estimated LEP values showed that the calculated value using the Rankine modified equation is 23.61% lower than the calculated value using the Rankine equation, which is a high percentage of difference. The estimated value using Abaqus CAE 2019 is 47.56% higher than the calculated value using the Rankine equation, which is also a high percentage of difference. https://creativecommons.org/licenses/by-nc/4.0/

show abstract

Section: Introductionmentioning

confidence: 99%

Lateral Earth Pressure Reduction on High-Filled Cut-and-Cover Tunnels Using Expanded Polystyrene Geofoam and Tire-Derived Aggregate

Flamarz,

Hajiazizi

2024

PJBAS

View full text Add to dashboard Cite

show abstract

Method of Average Vertical Earth Pressure for HFCCTs Based on Differential Settlement

Li,

He,

et al. 2024

Arab J Sci Eng

View full text Add to dashboard Cite

This paper presents a modified and simplified calculation method, taking into account the differential settlement between the soil columns surrounding the cut-and-cover. High-filled cut-and-cover tunnels (HFCCT) are usually subjected to high earth pressures above the top of the CCT due to an ultra-high backfill. However, the estimation methods for earth pressure above the top of CCT are ambiguous. Through the theoretical analysis of the average vertical earth pressure (AEP) at the top of the CCT, it is found that an additional earth pressure above the top of the overburden pressure is induced, and the magnitude is related to the differential settlement between interior and exterior soil columns. Thus, through a combined theoretical derivation and numerical analysis, a modified formula is proposed. The results show that the vertical earth pressure increment above the top of CCT can be linearly correlated to the differential settlement. In addition, the correlation needs to be calibrated by considering several effects on sites, such as slope angle, groove-width ratios, cross-sectional shape, and the type of backfill. The change in influencing factors has no effect on the function type of the p−δ fitting curve, but it will affect the coefficient k.

show abstract

Research on Structural Defect Characteristics and Influencing Factors for High-Fill Cut-and-Cover Tunnels in Mountainous Areas

Liu,

Xu,

Zhou

et al. 2024

Iran J Sci Technol Trans Civ Eng

View full text Add to dashboard Cite

Using expanded polystyrene geofoam and tire-derived aggregate in different forms to reduce vertical earth pressure on high-filled cut-and-cover tunnels

Cited by 4 publications

References 22 publications

Lateral Earth Pressure Reduction on High-Filled Cut-and-Cover Tunnels Using Expanded Polystyrene Geofoam and Tire-Derived Aggregate

Lateral Earth Pressure Reduction on High-Filled Cut-and-Cover Tunnels Using Expanded Polystyrene Geofoam and Tire-Derived Aggregate

Method of Average Vertical Earth Pressure for HFCCTs Based on Differential Settlement

Research on Structural Defect Characteristics and Influencing Factors for High-Fill Cut-and-Cover Tunnels in Mountainous Areas

Contact Info

Product

Resources

About