Unbound granular materials (UGMs) have advantages in their water storage and drainage capabilities in permeable pavement, which is a benefit for urban sustainable development. The plastic strain of UGM is a crucial mechanical property that affects its design and construction. During its service life, repeated load only, repeated load after infiltration, and simultaneous action with load and infiltration are the three inevitable working conditions that will impact plastic strain, especially dynamic water infiltration. How these working conditions influence plastic strain needs to be focused on and solved. This study conducted laboratory tests to investigate plastic strain considering factors such as loading strength and repetitions, as well as infiltration number and duration. The results showed that the plastic strain and plastic strain rate exhibited similar variations during the repeated load only test and repeated load after infiltration test. The plastic strain changed significantly with different infiltration numbers but had relatively small variations in terms of the plastic strain rate. Longer infiltration duration led to greater plastic strain. With the simultaneous action, the plastic strain presented different variation to the other two conditions. The first and second infiltrations had a more obvious influence on the plastic strain when infiltration was applied. Calculation models were established to predict the effects of loading strength and repetitions as well as infiltration number and duration on plastic strains. For the repeated load only test, an error of 4.6% was observed. In terms of the infiltration number and duration, the errors were found to be 18.5% and 8.5%, respectively. The power function and Sigmoidal Logistic model were used to establish calculation models under the simultaneous action test with a maximum error of 11.5% ranging from 100 to 60,000 repetitions. The proposed calculation models can characterize plastic strain under the three working conditions very well, which can help in the design and construction of fully permeable pavement.
As typical natural disasters in coastal areas, node failure and link interruption caused by typhoons directly threaten the operation stability of the freight multimodal transportation network (FMTN) in urban agglomerations. Such disruptions, in turn, restrict the sustainable development of the regional transportation and logistics system. In order to scientifically assess the FMTN resilience level in coastal area urban agglomerations under typhoon disturbances, this study constructs a resilience assessment method that integrates structural performance and functional performance. The Spatial Local Failure model and the Monte Carlo method, combined with fragility curves, are used to dynamically simulate the damage process of FMTN nodes and links by different typhoons intensities. By constructing FMTN resilience performance function, the resilience ratio is used to quantitatively assess the damage resistance and resilience maintenance level of FMTN under disturbances. This study also analyzes the resilience difference between FMTN and its sub-networks. The Typhoon Bebinca case is applied to validate the application of FMTN assessment method. The results show that FMTN exhibits stronger invulnerability and robustness under typhoon disturbances, and its resilience is significantly better than that of sub-networks. Specifically, when a strong typhoon hits, the FMTN resilience ratio only decreases by 0.13, while the resilience ratio of each sub-network decreases significantly by 0.21, 0.42, 0.46 and 0.57, respectively. FMTN resilience under typhoon disturbances is further assessed through an example analysis. And it verifies not only the comprehensive advantage of FMTN under typhoon disturbances but also the rationality and practicability of the assessment method. The findings can provide an important theoretical basis and technical support for resilience assessment, disaster prevention, mitigation planning, and the sustainable development of FMTN in coastal area urban agglomerations. It is of great practical significance to promote the efficient operation of China’s FMTN.