The graphene modified asphalt used in this study was prepared based on a highway project in Gansu Province. In this paper, the high temperature rutting resistance, low temperature cracking resistance, and water stability of SMA-13 asphalt mixture with asphalt (AH-70), SBS modified asphalt and graphene rubber composite modified asphalt were tested and analyzed comparatively by the rutting test, Schellenberg binder drainage test, Cantabro test, freeze-thaw splitting test, and beam bending test. The results showed that the graphene modifier improved the asphalt’s ductility and softening point significantly, and 0.4g graphene content was the threshold and its corresponding mixture performance index. In the other tests under the same conditions, the high temperature and water stability of SMA-13 mixtures of graphene rubber modified asphalt were the best, followed by SBS modified asphalt mixture, and matrix asphalt mixture. Compared with wood fiber, graphene modifier had no significant effect on SMA-13 mixtures’ low temperature performance. The use of graphene modifiers can enhance the adhesion between asphalt and aggregate and its asphalt has good consistency and viscosity. When compared with matrix asphalt and SBS modified SMA-13 mixtures, the water and high temperature stability of graphene modified asphalt mixture is better.

In this article, the factors affecting the friction coefficient between a box culvert’s sidewalls and surrounding soil and the box culvert’s mechanical behavior during the jacking process in construction were studied with an engineering example in Guangdong province, China. First, the principal factors that affected changes in the friction coefficient and its law were analyzed with self-development model testing. Second, in combination with 3D finite element simulation, both the stress and strain laws of a box culvert’s different parts were studied by considering changes in jacking distance, soil thickness, and drag reduction material. The results showed that with increasing jacking distance, both the curves of stress and strain on the roof and floor with jacking distance exhibited an “armchair” shape, while the web had a “trapezoid” shape as the box culvert was jacked into the subgrade. Both the thickness and characteristics of the cover soil on top of the box culvert had an essential influence on the stress and strain values of the box culvert’s structure. Water content’s effect on the friction coefficient decreased gradually when the water content exceeded its plastic limit. The optimal ratio of cement slurry to soil was approximately 1:4 in the project. It is also suggested that a paraffin and engine oil mixture can be used as a drag reduction material when jacking a box culvert.

There has been a long history for foundation treatment by quicklime pile, but as for establishing a more precise model formula used by actual construction, further research is needed to be done at present. Therefore, how to quantitate the factors affecting pile spacing is of great reference value for both actual constructions and theoretical studies. Based on the reference formula for handling weak foundation by lime pile and the practical problems in the western region, mathematical model analysis method is used to get a new model for high water content loess foundation treatment after considering the factors such as pile expanding, construction method, piles arrangement, and calcium oxide content. In this model, pile spacing coefficient is created and the model formula for different construction methods and different pile arrangements is also given. As a result, the reference formula used in high water content loess is somewhat conservative. The new model is also verified to be rational by the actual works at the end of the paper.

The construction phase of sports buildings is characterized by high carbon emission intensity, yet existing studies have largely focused on operational energy consumption and static life-cycle accounting, with no systematic investigation of the dynamic interactions among labor, materials, machinery, and environmental factors during construction. To fill this gap, this study develops an agent-based modeling (ABM) framework for a university natatorium in Shaanxi, China, to assess carbon emissions during the civil engineering construction phase and analyzes the independent and synergistic effects of labor, materials, machinery, and environmental factors. The simulation results show that, among single factors, material recycling achieves the highest reduction efficiency (57.93%, under the avoided-burden approach, representing a technical upper-bound estimate), followed by labor skill improvement (3.08%) and machinery maintenance (0.26%), while adverse weather increases carbon emissions by 13.20%. Multi-factor synergy analysis reveals that labor skill improvement buffers weather-induced increases (synergy: +610.49 t, 4.26%), and the full-intervention scenario achieves a 52.33% net reduction under adverse weather, though weather impacts cannot be fully offset. The proposed framework provides methodological support and a decision-making basis for low-carbon construction planning of natatoriums and similar buildings.