Grouting technology and construction schemes of a tunnel in aeolian stratum: a case study of Shenmu No. 1 tunnel

AbstractThe naturally formed aeolian sand dunes in northern Shaanxi exhibit unique engineering characteristics. Several challenges, such as the poor self-stabilization ability of the surrounding rock, difficultly in injecting grout, and insufficient construction experience, restrict the construction of road tunnels under this stratum. Therefore, in this study, a case study of the Shenmu No. 1 tunnel was conducted to investigate the engineering characteristics of aeolian sand tunnels, compare the grouting effects of commonly used grouting materials, and discuss the reinforcement effects of different construction schemes in aeolian sand tunnels. Based on a field grouting test, it was determined that it is difficult to inject ordinary cement grout into an aeolian sand layer. Furthermore, it was determined that superfine cement grout and modified sodium silicate grout can be injected, but the former exhibits a poor reinforcement effect. Additionally, results of numerical analysis indicated that an approach based on a concept of “horizontal jet grouting pile + benching partial excavation method with a temporary invert” is suitable for the construction of tunnels in aeolian sand in China.

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Research on Key Technologies of Construction Of Tunnel in Aeolian Stratum: A Case Study of Shenmu No. 1 Tunnel

10.21203/rs.3.rs-733467/v1 ◽

2021 ◽

Author(s):

Fei YE ◽

Xing Liang ◽

Xiaoming Liang

Keyword(s):

Sand Dunes ◽

Cement Grout ◽

Aeolian Sand ◽

Engineering Characteristics ◽

Jet Grouting ◽

Road Tunnels ◽

Construction Experience ◽

Northern Shaanxi ◽

Grouting Materials

Abstract The naturally formed aeolian sand dunes in northern Shaanxi have unique engineering characteristics. Several difficulties restrict the construction of road tunnels under this stratum, such as the poor self-stabilization ability of the surrounding rock, difficultly in injecting grout, and insufficient construction experience. Therefore, in this study, a case study of the Shenmu No. 1 tunnel was conducted to investigate the engineering characteristics of aeolian sand tunnels, compare the grouting effects of commonly used grouting materials, and discuss the reinforcement effects of different construction schemes in aeolian sand tunnels. Based on a field grouting test, it was found that it is difficult to inject ordinary cement grout into an aeolian sand layer; superfine cement grout and modified sodium silicate grout can be injected, but the former has a poor reinforcement effect. Through numerical analysis, it is found that an approach based on a concept of “horizontal jet grouting pile + benching partial excavation method with a temporary invert” is suitable for the construction of tunnels in aeolian sand in China.

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Sedimentological characteristics and morphology of the aeolian sand dunes in the eastern part of the UAE, a case study from Ar Rub' Al Khali

Sedimentary Geology ◽

10.1016/s0037-0738(98)00116-x ◽

1999 ◽

Vol 123 (3-4) ◽

pp. 219-238 ◽

Cited By ~ 38

Author(s):

M.I El-Sayed

Keyword(s):

Sand Dunes ◽

Aeolian Sand

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Research on Grouting Experiment in Aeolian Sand Tunnel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.382.316 ◽

2011 ◽

Vol 382 ◽

pp. 316-320

Author(s):

Yu Liang Qiu ◽

Wan Kun Zheng ◽

Bao Tong Shi ◽

Rui Huang

Keyword(s):

Portland Cement ◽

Sodium Silicate ◽

Single Particle ◽

Reference Value ◽

Aeolian Sand ◽

Jet Grouting ◽

Grouting Materials ◽

Penetration Grouting ◽

Selection Of

Portland cement, superfine cement and modified sodium silicate have been taken as grouting materials in the aeolian sand tunnel which is characterized by single particle, bad gradation and loose structure. In this paper, penetration grouting and rotary jet grouting have been adopted in site grouting experiment, whose effects are tested by excavation sampling test and field excavation detection. The grouting feature of aeolian sand formation has been revealed. In the meantime, the applicability of different kinds of grouting materials in aeolian sand tunnel have been clarified which provides useful significance and reference value on the selection of grouting parameter and construction in aeolian sand tunnel.

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Should We Expect a Disastrous Fire Accident in an Urban Road Tunnel? Literature Data Review and a Case Study for Selected Tunnels in Poland

Sustainability ◽

10.3390/su13116172 ◽

2021 ◽

Vol 13 (11) ◽

pp. 6172

Author(s):

Krystian Szewczyński ◽

Aleksander Król ◽

Małgorzata Król

Keyword(s):

Time Horizon ◽

Road Traffic ◽

Traffic Intensity ◽

Road Tunnel ◽

Urban Road ◽

Road Tunnels ◽

High Uncertainty ◽

Fire Outbreak ◽

Fire Accident

Urban road tunnels are a reasonable remedy for inconvenience due to congested road traffic. However, they bring specific threats, especially those related to the possibility of fire outbreak. This work is a case study for selected urban road tunnels. Considering tunnel specificity, road traffic intensity, and structure and based on the literature data for vehicle fire probability, the chances of a fire accident were estimated for selected tunnels in Poland. It was shown that low power tunnel fires could be expected in the 10–20-year time horizon. Although such threats cannot be disregarded, tunnel systems are designed to cope with them. The chances of a disastrous fire accident were estimated as well. Such events can occur when an HGV with flammable goods or a tanker are involved. Such accidents are fortunately very rare, but, on the other hand, that is the reason why the available data are scanty and burdened with high uncertainty. Therefore, a discussion on the reliability of the obtained results is also provided.

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Errors in documenting the subsoil and their impact on the investment implementation: Case study

Open Engineering ◽

10.1515/eng-2021-0074 ◽

2021 ◽

Vol 11 (1) ◽

pp. 744-754

Author(s):

Marzena Lendo-Siwicka ◽

Grzegorz Wrzesiński ◽

Katarzyna Pawluk

Keyword(s):

Construction Projects ◽

Organic Soils ◽

Cohesive Soils ◽

Engineering Model ◽

Limit States ◽

Uplift Pressure ◽

Geological Engineering ◽

Jet Grouting ◽

Geotechnical Category

Abstract Improper recognition of the subsoil is the most common cause of problems in the implementation of construction projects and construction facilities failures. Most often, their direct cause is the mismatch of the scope of geotechnical diagnosis to the appropriate geotechnical category, or substantive errors, including incomplete or incorrect interpretation in the creation of a geological-engineering model and often overlooked hydrogeological conditions. In many cases, insufficient recognition and documentation of geotechnical and/or geological and engineering conditions leads to damage and construction failures, delays in consider construction, and the increase of the investment budget. That’s why, in order to avoid the above, particular attention should be paid to proper geotechnical and geological-engineering documentation at the design and construction stages. The selected example of the investment analyzed errors in the geological-engineering documentation, which mainly concerned the lack of recognition of locally occurring organic soils, the incorrectly determined location of the groundwater table and the degree of compaction of non-cohesive soils, and numerous errors of calculated values of soil uplift pressure. The detection of the errors presented in the paper made it possible to select the correct technology for the construction of the sanitary sewage system and to increase the thickness of the horizontal shutter made of jet grouting columns in the area of the excavation. In addition, the article discusses the principles of proper calculation of limit states and subsoil testing, which have a significant impact on the implementation of planned investments.

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