• The Journal of Engineering Geology
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• v.18 no.1
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• pp.93-102
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• 2008

The use of lattice girder is increased at the tunnel site in Korea because of the several advantages over the traditional H-steel rib. The lattice girder supports the ground with shotcretes, forming a combined support system. Therefore, stress measurements at the lattice girder are necessary to calculated the ground loads. However, field measurements at the lattice girder are rarely performed at the tunnel site. The proper way of stress measurements for the lattice girder is not fully established in Korea. The correction of stress measurements at the shotcretes is often disregarded even though the measured stresses include non-stress related strains. Results of the stress measurements obtained from the lattice girder and non-stress shotcretes are used to improve the credibility of the stress measurements at the primary lining.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.2
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• pp.177-192
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• 2010

The field measurements on the shotcrete lining are usually performed during the tunnel construction. However, the credibility of the measurements is not certain because of the non-stress related strains occurring in the shotcrete, the uncertainty of the deformation modulus of the shotcrete, and the intrinsic difficulties involved in the strain measurements in the shotcrete. The problem related to the field measurements on the shotcrete is investigated using the review of the previous studies and the field measurement performed for this study. A method for the correction of stress measurements at the shotcrete lining, considering the non-stress related strains, is suggested using the literature review and the actual measurements obtained from the non-stress shotcretes. The deformation modulus used for the calculation of the stress acting on the shotcrete is also suggested.