###### Abstract  
The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel's performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/\({}^{\circ}\)C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 \({}^{\circ}\)C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection. assembled supporting structure; foundation pit; thermal stress; full-scale test; numerical simulation +
Footnote †: journal: Applied Sciences  
**Citation**: [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Internal Force on and Deformation of Steel Assembled Supportingcost-effective; they can also make rational use of the self-stabilization ability of soil and can use soil as a component of the supporting structure, but it is difficult to apply them to areas with poor soil qualities [5; 6]. The soil mixing walls have reliable structural strength, good water-retaining and anti-seepage performance, and they can be applied to deep foundation pits with multi-point supports. However, the interaction between mixing piles and steel supports should be further studied [7]. Diaphragm walls are a type of support with better performance because of their high rigidity and good sealing effect. However, due to their high cost, they are often used in foundation pits with high safety requirements [8; 9]. With the popularization of the concept of green building, the sustainable supporting structure technology of deep foundation pits has gradually become one of the key development directions of geotechnical engineering. Steel assembled section supports have the advantages of sufficient safety reserve, a short construction period, low cost, and recyclability [10; 11; 12]. Among them, steel H-section supports are economical and efficient with a higher optimized cross-sectional area distribution and a higher reasonable strength-to-weight ratio [13; 14]. Moreover, their interface characteristics are obviously superior to the traditional steel I-section supports, steel channel supports, and steel angle supports. However, this type of supporting structure is significantly affected by the temperature variation. In fact, when there is a large temperature gradient, these supporting structures experience serious thermal expansion and cold contraction. [PERSON] et al. observed that the supporting load and the temperature increase synchronously in a deep foundation pit, but they do not decrease continuously when the temperature declines. In addition, a new method was proposed for separating soil pressure and temperature pressure in foundation pit supports [15]. [PERSON] developed a relationship between the stress, deformation, and temperature of an anchor in a deep foundation pit by a rotary spray support based on the measured data.