Mudflows are natural phenomena starting from landslides and presenting high impact when they occur. They generate great catastrophes in their path because most of the time there is no indication prior to the failure that triggers them. Understanding how mud is transported is of great importance in infrastructure projects that coincide with hillside areas due to the high risk of occurrence of this phenomenon by cause of the high slopes, which can involve great risks and produce disasters that involve great costs. This work presents the evaluation of mudflows, from the implementation of a laboratory scale experiment in a consistometer with its calibration and validation from numerical models to estimate rheological parameters of the material. Tests were also carried out in an open channel in the laboratory, based on the data previously obtained considering the behavior of the material as a both Newtonian fluid and non-Newtonian fluid. The experiment considered a channel with dimensions of 3 m long, 0.5 m high and 0.7 m wide with slope control, and a mud composition of silty material with 60% moisture. The tests were conducted with slopes of 5%, 10%, 15% and 20%. The numerical models were carried out in ANSYS FLUENT software. In addition, the calibration data of the numerical model were used for a real case study, simulating the slip flow occurred in Yangbaodi, in the southeast of China, occurred on September 18, 2002. The results of the numerical models were compared with the experimental results and show that these have a great capacity to reproduce what is observed in the laboratory when the material is considered as a non-Newtonian fluid. The model reproduced in an appropriate way the movement of the flow at laboratory scale, and for the aforementioned case study, some differences in the final length of deposition were noticed, achieving interesting results that lead the use of the calibrated model towards the estimation of risks due to the mudflow occurrence.

Pressurized water pipelines buried in an urban environment are prone to bursting failures, threatening public safety and traffic convenience. The limited studies in literature just focused on soil fluidization while few studies considered ground failure, shear strain, soil erosion and the influence of leakage locations during pipe bursts. In this study, extensive experimental tests along with a finite difference method - discrete element method (FDM-DEM) solid-fluid coupling analysis were conducted to investigate these issues. It was disclosed that the failure development during pipe bursts can be divided into three stages, i.e., seepage diffusion, erosion cavity expansion, and soil fluidization. By digital image correlation (DIC) analysis of the experimental results, a wedge-shaped displacement zone in ground was identified, with peak shear strain near its boundaries. Moreover, it was revealed that leakage locations affected the expansion origin of erosion cavity; as the burial depths increased, the ground heave range increased linearly; the maximum water outflow distance was closely related to the internal pressures of buried pipeline, which could be modeled by a square root formula based on turbulent jet theory. Mesoscopic analyses revealed that finer particles were more susceptible to erosion during pipe bursts because of the low possibility of forming strong connections with surrounding particles. The findings yielded from this study can enhance the understanding of pipe bursts and help professionals mitigate potential damage.

The rheological modeling of soil-drum interaction in the vibratory compaction process is a complex process. This paper aims to describe the behavior of soil-drum interaction through lumped parameter modeling. The amplitude of the vertical motion is evaluated for dynamic conditions using the rheological models (generalized and advanced Kelvin-Voigt-based models) and compared with the experimental results obtained from weakly cohesive soil compaction. Different modeling approaches are considered, and the results reveal that the properties of the soil as input play a vital role in the accuracy of the modeling.

The process of permeation damage of the filling medium in the fracture is critical to the stability of the fractured rock mass. This study focused on the seepage failure process of filling materials in fractures and faults. To investigate the effects of axial stress and clay content, a series of experimental tests were conducted on internally unstable granular soil specimens with different clay contents under different axial stresses. The variations of flow rate and hydraulic conductivity were recorded and analyzed during the tests, and the typical process of seepage failure was summarized. The flow rate, hydraulic conductivity, and their growth rates were found to be smaller under high axial stress compared to low axial stress, and the flow rate of samples with higher clay content was smaller than those with lower clay content. Initially, the hydraulic conductivity decreased slightly due to clay and fine particle rearrangement, and remained nearly constant when the hydraulic gradient was small. However, as the hydraulic gradient increased, the hydraulic conductivity began to increase in response to the loss of clay and fine particles.

Long integral bridges experience an enhanced cyclic soil structure interaction with their granular backfills, especially due to seasonal thermal loading. For numerical modelling of this interaction behaviour under cyclic loading, it is important to employ a suitable constitutive model and calibrate it thoroughly. However, up to the present, experimental data and calibrated soil models for this purpose with focus on typical well-graded coarse-grained bridge backfill materials are rarely available in the literature. Therefore, one aim of this paper is to present results of a comprehensive cyclic laboratory testing programme on highly compacted gravel backfill material. Based on this, a hypoplastic constitutive model with intergranular strain extension for small strain and cyclic behaviour is calibrated and evaluated against the experimental test data. The soil model's abilities and limitations are discussed at element test level. In addition, cyclic FE analyses of an integral bridge are conducted with several hypoplastic parameter sets from the literature and compared to the calibrated gravel backfill material. The investigation highlights that poorly-graded sands show significantly smaller cyclic earth pressures compared to well-graded gravels intended for the backfilling of a bridge. The soil structure interaction behaviour is clearly governed by the general soil model stiffness, including the small strain stiffness.

To provide foundational data for parameter design and performance analysis of high-performance processing equipment, the collision model between jujube-parts and the parameter effects on coefficient of restitution (COR) were investigated. Jujube samples from the sandy lands of southern Xinjiang during the harvest season were utilized, with experimental factors including collision angle, falling height, collision material, moisture content, and collision parts. Single-factor tests and mixed orthogonal tests were conducted to explore the impact of parameter on COR. Utilizing the specular reflection principle, a 3D impact analysis of jujube was performed, and a kinematic model of the falling and impact process was established to determine the COR. Results indicate that the COR of Jun (Zizyphus jujuba cv. Junzao) is higher than that of Hui (Zizyphus jujuba cv. Huizao), and the ventral part exhibits a higher COR compared to the other four parts. Collisions with steel yield higher COR values compared to soil. Furthermore, for collisions with steel material, both Jun and Hui exhibit a decrease in COR with increasing falling height and moisture content, while the COR increases with an increase in collision angle. The influencing factors on COR follow the order of collision material > variety > moisture content > collision angle > falling height > collision part. These findings offer valuable insights for jujube processing research and for preventing mechanical damage to jujube fruits.

Testing of small-scale physical models of masonry structures can be useful both to study Soil Structure Interaction problems and to provide large enough datasets to statistically validate the global level assumptions of masonry numerical models. This paper proposes the use of a sand -based Binder Jet 3D printer to manufacture 1:10 scaled physical models of masonry walls, that can be used within a centrifuge. As such printers can only print one material, mortar is emulated by controlling the micro -geometry of the printed material at the position of the joints (i.e., by printing joints). Walls were printed and tested in compression and cyclic shear under fixed -fixed conditions and constant compressive load. Different notch geometries were tried. The tested specimens were found to behave similarly in compression and shear to full scale masonry walls. A numerical model using a concrete damage plasticity model was built in Abaqus. It captured the cyclic response of the masonry walls with a reasonable accuracy. Therefore, such small-scale models can be used to expand centrifuge modeling in structural engineering.

Seismic isolation aims to prevent the direct transmission of seismic wave energy to the main resistant structure. Typically, this is achieved by using a flexible support system that isolates the base of the structural system from the ground, absorbing the relative deformation at the soil-structure interface. Meanwhile, the main structure tends to move as a rigid body on this flexible support. This article proposes an alternative approach for the dynamic characterization of shredded rubber, which is used in geotechnical seismic isolation (GSI). Traditional testing methods are expensive and require specialized equipment, making them less practical for routine determination. The article details the most important parameters needed to evaluate the applicability and effectiveness of the material in the context of GSI. The parameter of interest, i.e. the transverse elasticity module GR, was calibrated numerically from an experimental model of a column of shredded rubber subjected to free vibrations tests. The results were consistent with those obtained from resonant column and hollow cylinder tests. In this way, it is shown that the presented approach is capable of providing valid estimations of the transverse modulus of elasticity of shredded rubber.