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Intelligent design is a trend in geotechnical engineering. However, a middle link between demand identification and intelligent design is missing in anchor engineering, resulting in lower efficiency in terms of the interaction between the anchor components, geological body and modeling information. To address this challenge, this paper proposes a method for modeling a three-dimensional anchor engineering information model based on sparse boreholes. This method includes three parts: modeling the geological body, integrated modeling of the anchor components and the geological body, and multiple information assignments based on the anchor model. The feasibility was validated in actual engineering scenarios by using neural networks and rendering engines. The results showed that the prediction accuracy of the strata improved by 17.69%, the modeling efficiency increased by double, and engineering information was fit to the model well. This paper has the application potential to achieve intelligent design in anchor engineering.

Red bed composite polymers composed of weathered red bed soil, adhesive materials, and water-retaining materials have been applied as a new type of material for environmental restoration. However, the promotion and application of this material has been limited by a lack of understanding of its action mechanism in environmental restoration. The objective of this study is to innovatively propose a water‒soil-air‒plant mutual feedback mechanism based on this material. Therefore, water‒soil-air‒plant mutual feedback tests were conducted in this study under 3 initial water contents and 10 red bed composite polymers ratios. Key parameters, namely, water content, soil conductivity, pH, temperature, O2 and CO2 contents, pigeon pea (Cajanus cajan) germination number and plant height were monitored and analyzed. As the results, a mutual feedback mechanism driving water retention, soil consolidation, air retention, and plant rooting was revealed under the application of red bed composite polymers. And, suitable environments and optimal compositions for this material are proposed. The study results provide a theoretical basis for the large-scale application of red bed composite polymers. [ABSTRACT FROM AUTHOR]

Red beds belong to slippery formations, and their rapid identification is of great significance for major scientific and engineering issues, such as geological hazard risk assessment and rapid response to geological disasters. Existing research often identifies red beds from a qualitative or semiquantitative perspective, resulting in slow recognition speed and inaccurate recognition results, making it difficult to quickly handle landslide geological disasters. Combined with the correlation between red beds' geomorphic characteristics, mineral compositions, and chemical compositions, this study established a preliminary identification quantitative criterion based on the basic chemical composition combination rules (SiO2+Al2O3 , Al2O3/SiO2 , FeO+Fe2O3 , Fe2O3/FeO , K2O+Na2O , Na2O/K2O , CaO+MgO , and MgO/CaO) in the red beds. Following this, we perform principal component analysis on the basic chemical composition combination rules mentioned above. The results indicate that simultaneously meeting the following principal component features can serve as a rapid quantitative criterion for distinguishing red beds from other rocks: F1=-3.36 –23.55; F2=-23.00 –3.11; F3=-10.12 –4.88; F4=-2.21 –4.52; F5=-0.97 –7.30; and F=-0.67 –1.89. By comparing the chemical composition combinations of 15 kinds of rocks collected from China in this study, it is proven that the quantitative criterion proposed in this study is effective. The study results can be used for rapid identification of red beds, achieving risk assessment and rapid response to geological disasters such as landslides. [ABSTRACT FROM AUTHOR]

The mechanism for improving soil with high-performance ester material is not yet clear, especially changes in soil moisture under dry–wet cycling conditions. Soil moisture is closely related to its ecological performance, which also leads to a lack of scientific bases for the application range, climate conditions, and long-term performance evolution evaluation of high-performance ester materials in ecological restoration. Our research revealed an optimal ratio for the amount of high-performance ester materials that can improve soil moisture and ecological performance under multiple dry–wet cycling conditions. Dry–wet cycling experiments and planting tests were conducted to study the soil moisture improvement mechanism and the changes caused by high-performance ester materials. Changes in the soil's moisture, EC, and ecological performance were explored. The results indicate that ester materials can effectively improve soil moisture and EC. Even after multiple dry–wet cycles, ester materials can still play an effective role in improving soil moisture and ecological performance. An optimal ratio for the amount of high-performance ester materials was also found. This research reveals the improvement mechanism for ester materials on soil moisture and ecological performance under dry–wet cycling conditions. Our results provide new data and technical guidance for the improvement of soil moisture and ecological restoration by high-performance ester materials. [ABSTRACT FROM AUTHOR]

Sandstone is an important and common engineering rock, and understanding the meso/macroscale mechanical properties of sandstones under different confinements are crucial for engineering safety. It is still difficult to correlate the mesoscale bonding parameters and macroscale mechanical behavior. In this paper, the Hoek–Brown parallel bond correlation model (HB-PBCM) is proposed based on the mesoscale analysis of the parallel bond model (PBM). The mathematical analytical expression of HB-PBCM is derived from the sensitivity analysis of the PBM parameters to the Hoek–Brown criterion strength parameters. The model is able to reproduce both the PBM and HB parameters obtained from laboratory tests. The parameters were validated via numerical tests, where the final strength and failure patterns of sandstones are shown to be consistent with those via real experiments. Combined with the numerical and experimental results, we find that the macroscale brittle‒ductile transition of sandstone is characterized by the alteration of the tensile-to-shear crack ratio, different mesoscale crack distributions, and mesoscale crack accumulation rates. [ABSTRACT FROM AUTHOR]

3D stratum roaming can visualize the complex geomorphology, underground structure and stratum distribution of geotechnical engineering. Conventional 3D stratum roaming technology is generally aimed at roaming outside the 3D stratum model but rarely roams inside the 3D stratum model, and the efficiency of switching between external and internal roaming is low. In practical engineering, especially in geological and geotechnical engineering, the underground structure and stratum situation are critical. Therefore, focusing on this problem, this paper adopts a three-dimensional roaming engine to connect the inside and outside of a three-dimensional model. Based on an internal and external boundary identification method, the combination of external roaming and internal roaming of the three-dimensional stratum model is implemented by using a stratum virtual surface, and lightweight loading is carried out by controlling the stratum virtual surface to establish the internal and external roaming of the 3D stratum model, and to give full play to the advantages of lightweight loading to provide more intuitive and comprehensive geological information for the project. [ABSTRACT FROM AUTHOR]

In order to explore an efficient slope soil ecological restoration method that is environmentally friendly and conducive to plant growth, this paper conducted a study on ecological aggregations based on polymer composite materials. This paper developed ecological mini-aggregations, including ecological mini-clusters and ecological mini-bags, which can be used for the restoration of slopes with different steepnesses and surfaces. The developed materials are environmentally friendly and have good ecological performance. To study the mechanical stability, erosion resistance, and ecological performance of the ecological mini-aggregations, we conducted laboratory erosion resistance stability tests, shear strength tests, and plant growth tests, and variance analysis of the test result data was conducted to reveal the effects and laws of the aggregation materials. The results show that the mechanical stability of ecological mini-aggregations is strong, the erosion resistance is high, and the ecological performance is favorable. The performance is sufficient for slope soil ecological restoration, and there is an optimal material ratio for the addition of materials to ecological mini-aggregations. The above research revealed the mechanism controlling polymer composite materials in the development of ecological mini-aggregations; these materials can be included to create ecological mini-aggregations that exhibit strong erosion resistance stability and ecological performance. These research results can provide new technical means for the efficient ecological restoration of slopes. [ABSTRACT FROM AUTHOR]

Ester materials have become a significant topic in ecological restoration because of their degradability and lack of pollution. However, these artificial materials have issues such as high resource consumption and high cost. Therefore, finding a scientific substitute for ester materials is crucial to reduce costs. This study proposes the use of weathered red-bed soil to partially replace ester materials. Orthogonal coupled compounding and ecological effect tests were performed to analyze the soil improvement mechanism based on the mineral composition, soil structure, and electrical conductivity properties of the weathered red-bed soil. The experimental findings indicated that the soil modified using ester materials exhibited improved strength, water retention, and aeration owing to changes in the soil structure. Plant germination and height increased by 55% and 37 mm, respectively, when using a ratio of 15 g/m2 absorbent ester material, 2.5 g/m2 adhesive ester material, and 5% weathered red-bed soil. Through this approach, the amount of ester material to be used could be further reduced by 75%. The weathered red-bed soil offers improved ecological effects by altering the physical, mechanical, and hydraulic properties of the soil structure. This study presents a theoretical foundation for ecological conservation using weathered red-bed soil as a substitute for certain ester materials. [ABSTRACT FROM AUTHOR]

Red beds are widely distributed in various regions of China. Adapting measures to adjust to local conditions and using nearby materials to ecologically protect slopes, mines, and other engineering projects are methods advocated by environmental protection. A mud film of the weathered soil of red beds with improved materials for insulation and entropy preservation is commonly used in engineering ecological protection, and its self-sustainability is an important indicator with which to measure the protective effect; however, most of the commonly used improvement materials in production have high concentrations of chemical substances and high costs, causing environmental pollution. In response to this issue, this study has developed four new composite improved materials using waste paper as raw material. The low temperature resistance (−20 °C, 0 °C), high temperature resistance (40 °C, 60 °C, and 80 °C), and recyclability (dry and wet cycle: zero, one, two, and three times) of the four materials were tested. Under the conditions of changing the addition amounts of four new self-developed composite materials (0 g, 10 g, 20 g, 30 g, 40 g, 50 g, 60 g, 70 g, 80 g, 90 g, and 100 g), experiments were conducted on the thin-layer property, corrosion resistance, and flexibility of the mud film of weathered soil of red beds, and they were compared with conventional materials studied by the team in the early stage. At the same time, outdoor on-site testing was conducted. The experimental results indicate that the self-developed new composite improvement material has a good improvement effect on the self-sustainability and ecological protection effect of the mud film of weathered soil of red beds. This article summarizes the improvement mechanism and control factors of self-developed new composite materials in the self-sustainability of the mud film of the weathered soil of red beds, improves the suitability of engineering ecological protection, and develops green and low-cost engineering ecological protection technology. [ABSTRACT FROM AUTHOR]

Calculation and characterization of the whole process of internal microscopic damage to surface damage in red-bed soft rock is a theoretical research difficulty and an urgent need for engineering safety protection. However, the current study cannot accurately and directly correlate internal and external damage. Therefore, in this paper, a coupled tensor–DEM–FEM model is proposed to deal with surface damage by indoor triaxial test digital image processing (DIC), internal damage by FJM acoustic emission study, and internal and external damage by moment tensor correlation. The study demonstrates that the whole process damage process of the red-bed soft rock peak front can be divided into six distinct phases, with early damage beginning with the elastic phase; the local strain divergence value begins to spiral out of control during the period of crack acceleration development; the overall acoustic emission intensity distribution is in the range of [−8.5, −6.3] in two dimensions and in the range of [−11, −9] in three dimensions; the R were between −40 and 40, which corresponded to the results of the indoor tests. A model has been developed that allows a direct reflection of the whole damage process. The method can be used to better understand the disaster mechanism and guide engineering practice. [ABSTRACT FROM AUTHOR]

Ecological slope protection projects (such as the reinforcement of low slopes by plants and ecological restorations of the soil of high steep rocky slopes) are essential for restoring the natural environment. In this study, red bed soil and composite polymer adhesive materials were used to develop an ecological membrane for application in slope ecological protection. The basic physical and mechanical properties of the ecological membranes with different material percentages were studied through tensile strength test and viscosity test, the effect of different material percentages on the properties of ecological membranes was studied, and the soil protection performance and ecological restoration performance were studied through anti-erosion and plant growth tests. The results show that the ecological membrane is soft and tough, with high tensile strength. The addition of the red bed soil can enhance the strength of the ecological membrane, and the ecological membrane with 30% red bed soil has the highest tensile strength. The ecological membrane has considerable tensile deformation capability and viscosity, and up to 100% by mass, the more composite polymer adhesive materials added, the greater the tensile deformation capability and viscosity. And the ecological membrane can enhance the anti-erosion performance of the soil. This study clarifies the development and technology of the ecological membrane, reveals the effect of different material percentages on the properties of ecological membrane, and analyzes the slope ecological protection mechanism of the ecological membrane, thereby providing theoretical and data support for its development, improvement, and application. [ABSTRACT FROM AUTHOR]

Natural redbeds are widely distributed throughout China. Ecological restoration entails implementing measures according to the local conditions and obtaining local materials, ensuring ecological environment conservation and restoration in a scientific manner. The mud skin of weathered redbed soil is often used to control soil desertification and repair slope, and its integrity is important to measure the repairing effect. However, most of the materials used for the improvement of weathered redbed soil contain harmful chemicals, bear high costs, and aggravate environmental pollution. At present, the knowledge about different kinds of improvement materials for Chinese different zones is unclear. To solve this problem, we considered naturally weathered redbed soil as the raw material, selected 77 kinds of improved materials, and tested the integrity of the natural redbed weathered soil after adding the improved material; then, we compared it with the natural redbed weathered soil with no added materials. Then, we put forth a classification standard for the materials, discussed the driving environmental factors, formulated the suitable zoning of the materials, and defined the improvement effects of different materials on the weathered redbed soil in different regions of China. The results suggested that, for weathered redbed soil, nano water-based adhesives were most suitable for the south-western, north-western, south-eastern, north-eastern, and northern regions of China and can be widely used in other regions as well. Starch was the least suitable material for the north-western, north-eastern, and northern regions of China. The most unsuitable material for South-West China was larch tannin extract; wormwood straw was the most unsuitable for South-East China. The modified material that was not suitable for use in most zones was starch. Thus, our study provides a concrete scientific basis regarding the effectiveness of different materials in addressing natural hazards caused by weathered redbed soil in China. [ABSTRACT FROM AUTHOR]