ABSTRACT
Temperature loads can be a significant part of the total design loads of struts in open excavations. Since struts are critical structural elements for the safety of retaining wall systems, a reliable estimation of both temperature variations and temperature restraint coefficient is important. Temperature variations are defined in design codes, however this is not the case for the temperature restraint coefficient. Recommendations for the temperature restraint coefficient can be found e.g. in CIRIA. This paper presents evaluations of the temperature restraint coefficient based on strut temperature measurements and strut force (strain gauge) measurements on RD pile, secant pile and sheet pile walls constructed with up to four steel strut levels on the E05 Korsvägen project in Gothenburg, Sweden. Excavations for different construction pits up to 20 m deep with strut lengths up to 60 m have been studied. A large variation of the restraint coefficient is found and correlations with distance of the struts above the rock, stiffness of the soil on the active side and wall bending stiffness are each investigated. The study findings can assist with establishing a differentiated basis for temperature restraint coefficients on future projects with similar conditions.
