Stabilization Behavior and Performance of Loess Using a Novel Biomass-based Polymeric Soil Stabilizer

2019 ◽  
Vol 25 (2) ◽  
pp. 103-114
Author(s):  
Shengyan Pu ◽  
Yaqi Hou ◽  
Jin Ma ◽  
Yan Zou ◽  
Liu Xu ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Erosion Resistance ◽  
Loess Soil ◽  
Strength Properties ◽  
Water Stability ◽  
Soil Stabilizer ◽  
Stabilizer Concentration ◽  
Loess Particles ◽  
Green Strategy ◽  
And Performance

ABSTRACT Serious soil erosion can endanger human survival and sustainable development. Therefore, simple and highly efficient soil stabilizers that can be used to treat loess soil, which has poor water stability and easily disintegrates, are a topic of concern for researchers. In this work, a biomass-based polymeric soil stabilizer (CXZ) was prepared using a “green” strategy with polymerization of carboxymethyl cellulose and xanthan gum. A direct shear test, unconfined compressive strength properties, water stability, and erosion resistance were systematically investigated to test the stabilization performance. The stabilizer agglomerated small loess particles into large aggregates through “coating” and “weaving” effects to increase the cohesion, water stability, and erosion resistance significantly, as demonstrated by Fourier transform infrared spectroscopy and scanning electron microscope. Furthermore, in a 30-day growth experiment, the number of alfalfa plants and the plant height in stabilized loess both increased with the increase in CXZ stabilizer concentration. This work provides insight into a novel biomass-based soil-curing agent, broadening its applications in loess remediation and soil erosion control.

Relative contribution of root physical enlacing and biochemistrical exudates to soil erosion resistance in the Loess soil

CATENA ◽  
2017 ◽  
Vol 153 ◽  
pp. 61-65 ◽  
Author(s):  
Qiang Li ◽  
Guo-Bin Liu ◽  
Zheng Zhang ◽  
Deng-Feng Tuo ◽  
Ru-ru Bai ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Erosion Resistance ◽  
Loess Soil ◽  
Relative Contribution

scholarly journals Evaluation of a Cold-Mixed High-Performance Polyurethane Mixture

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Sun Min ◽  
Yufeng Bi ◽  
Mulian Zheng ◽  
Sai Chen ◽  
Jingjing Li
Keyword(s):  
Energy Consumption ◽  
High Performance ◽  
Greenhouse Gas Emission ◽  
Asphalt Mixture ◽  
Temperature Stability ◽  
Water Stability ◽  
High Temperature Stability ◽  
Forming Mechanism ◽  
And Performance

The energy consumption and greenhouse gas emission of asphalt pavement have become a very serious global problem. The high-temperature stability and durability of polyurethane (PU) are very good. It is studied as an alternative binder for asphalt recently. However, the strength-forming mechanism and the mixture structure of the PU mixture are different from the asphalt mixture. This work explored the design and performance evaluation of the PU mixture. The PU content of mixtures was determined by the creep slope (K), tensile strength ratios (TSR), immersion Cantabro loss (ICL), and the volume of air voids (VV) to ensure better water stability. The high- and low-temperature stability, water stability, dynamic mechanical property, and sustainability of the PU mixture were evaluated and compared with those of the stone matrix asphalt mixture (SMA). The test results showed that the dynamic stability and bending strain of the PU mixture were about 7.5 and 2.3 times of SMA. The adhesion level of PU and the basalt aggregate was one level greater than the limestone, and basalt aggregates were proposed to use in the PU mixture to improve water stability. Although the initial TSR and ICL of PU mixture were lower, the long-term values were higher; the PUM had better long-term water damage resistance. The dynamic modulus and phase angles (φ) of the PU mixture were much higher. The energy consumption and CO2 emission of the PU mixture were lower than those of SMA. Therefore, the cold-mixed PU mixture is a sustainable material with excellent performance and can be used as a substitute for asphalt mixture.

The Temporal Dynamics of Cynodon Dactylon Soil - Root System in Soil Conservation and Slope Reinforcement

2013 ◽  
Vol 838-841 ◽  
pp. 675-679 ◽  
Author(s):  
Miao Zhang ◽  
Fang Qing Chen ◽  
Jin Xia Zhang
Keyword(s):  
Shear Strength ◽  
Soil Erosion ◽  
Root System ◽  
Soil Conservation ◽  
Erosion Resistance ◽  
Cynodon Dactylon ◽  
Temporal Dynamics ◽  
Resistance Coefficient ◽  
Slope Reinforcement ◽  
Riparian Species

Cynodon dactylon has become a dominant riparian species in the reservoir region after the Three Gorges project was finished. In order to determine the effect of the species in soil conservation and slope reinforcement and the variation over time, the soil erosion resistance and shear strength of plants soil-root systems were tested during different seasons in a year through control experiment. Results showed that C. dactylon roots enhanced significantly soil conservation and slope reinforcement. The tensile strength of C. dactylon roots reached from 65.34 to 91.22Kpa/mm2 after three to twelve month growth, so did the soil erosion resistance coefficient from 0.34 to 0.86, shear strength from 20.82 to 25.98Kpa increasing by 39.62%, 154.90% and 24.74% respectively. We conclude that the temporal dynamics of C. dactylon roots influenced the performance of soil-root system in soil conservation and slope reinforcement.

scholarly journals Study on the Stabilization Mechanisms of Clayey Slope Surfaces Treated by Spraying with a New Soil Additive

2019 ◽  
Vol 9 (6) ◽  
pp. 1245 ◽  
Author(s):  
Cuiying Zhou ◽  
Shanshan Zhao ◽  
Wei Huang ◽  
Dexian Li ◽  
Zhen Liu
Keyword(s):  
Organic Polymer ◽  
Molecular Volume ◽  
Water Stability ◽  
Infiltration Depth ◽  
Infiltration Process ◽  
Soil Particles ◽  
Soil Stabilizer ◽  
Polymer Stabilizer ◽  
Infiltration Tests ◽  
Clayey Slope

The topsoil of a clayey slope is easily washed off by rain due to its loose structure. To protect the slope surface, in recent years, several types of non-traditional soil additives have been used by means of mixing with soil. In this work, a new organic polymer soil stabilizer, named aqua-dispersing-nano-binder (ADNB), was sprayed on the soil surface to stabilize the topsoil of a clayey slope. To understand the interaction between the polymer and soil particles during the infiltration process as well as the stabilization mechanism, infiltration tests, water stability tests and scanning electron microscopy (SEM) analyses were performed with different polymer contents. The infiltration tests showed that the infiltration rate of the polymer stabilizer in the soil was slower than that of water due to its characteristics of easy adhesion to soil particles, poor fluidity and large molecular volume. The maximum effective infiltration depth was achieved in the specimen treated with 2% ADNB, and the minimum was achieved in the specimen treated with 5% ADNB. The water stability of the soil increased with the content of the soil stabilizer in the soil aggregates with diameters of either 5–10 mm or 10–20 mm. The SEM analysis showed that the quantity of polymer decreased with infiltration depth; a polymer membrane was formed on the surface of the topsoil and chains were formed inside. The amelioration of the soil water stability may have been due to the bonding between soil particles and polymers generated after evaporation of water in the emulsion. The polymer stabilizer could be applied to improve the erosion resistance of the slope topsoil and reduce soil loss.

Vertical variation of soil erosion resistance in the water-level fluctuation zone of the Three Gorges Reservoir, China

2020 ◽  
Author(s):  
Hai Xiao
Keyword(s):  
Soil Erosion ◽  
Three Gorges Reservoir ◽  
Erosion Resistance ◽  
Three Gorges ◽  
Stream Power ◽  
Vertical Variation ◽  
The Three Gorges ◽  
Unit Energy ◽  
Water Level Fluctuation Zone ◽  
Soil And Water

<p>The operation of the Three Gorges Reservoir (TGR) altered the distribution of the soil properties, the plant community composition and biomass in the water-level fluctuation zone (WLFZ). However, the vertical variation of soil erosion resistance in the WLFZ of the TGR is still unclear and need to be further evaluated. The objectives of this study were to assess the vertical variation of soil resistance to rill erosion in the WLFZ of the TGR and to identify the factors influencing these variations. Soil samples from 150-155 m, 155-160 m, 160-165 m, 165-170 m and 170-175 m were taken along a slope profile at the same time from the WLFZ of the TGR area. All the samples subjected to scour under the combinations of five slope gradients (8.74%, 17.63%, 26.79%, 36.40% and 46.63%) and five flow rates (5, 10, 15, 20 and 25 L min<sup>–1</sup>) by using a slope-adjustable steel hydraulic flume (4 m length, 0.4 m width, 0.2 m depth). The results showed that soil properties and biomass parameters were affected by the elevations of the WLFZ. The average soil detachment capacity fluctuated with the increase of elevation, maximum and minimum value of  which were located at the 165-170 m and 155-160 m, respectively. The soil detachment capacity was significantly negatively correlated with MWD (P<0.05), but not positively correlated with other properties (P>0.05).  The rill erodibility also fluctuated with the increase of elevation. Correlation analysis showed that rill erodibility corresponding to runoff shear stress and stream power respectively had significantly negative correlation with MWD (P<0.05), and rill erodibility corresponding to unit energy of water-carrying section had significant negative correlation with MWD (P<0.01). Therefore, the soil aggregate stability was the major factor responsible for the vertical variation in soil erosion resistance. In addition, critical shear stress, critical stream power and critical unit energy of water-carrying section ranged from 1.1950 to 1.6427 Pa, from 0.0132 to 0.3045 N•m<sup>-1</sup>•s<sup>-1</sup> and from 0.0052 to 0.0062 m, respectively, all of them showed obvious fluctuations with the increase of elevation. These research results highlighted the effect of elevation on soil erosion resistance in the WLFZ and provide theoretical guidance for the establishment of soil and water loss prediction model as well as the development of soil and water conservation planning and controlling in the TGR area.</p><p> </p>

Research on the Technologyof Anti-Erosion and Vegetation Promotion for Pisha Sandstone Region in the Middle Yellow River Basin

2020 ◽  
Author(s):  
Peiqing Xiao ◽  
wenyi yao ◽  
pan zhang ◽  
chunxia yang
Keyword(s):  
Soil Erosion ◽  
Field Experiments ◽  
Erosion Resistance ◽  
Surface Composition ◽  
Yellow River ◽  
High Tech ◽  
Growth Promoter ◽  
Dam Construction ◽  
Allocation Model ◽  
Vegetation Growth

<p>Pisha sandstone region is the most vulnerable and the most dramatic area of soil erosion, and it is also the concentrated area of the coarse sediment entering into the Yellow River. It is of great significance to research the anti-erosion and vegetation promotion technology in the Pisha sandstone region. Based on the new concept of anti-erosion and vegetation promotion, surface composition, chemical properties and particle structure of the Pisha sandstone particles were analyzed, and the lithologic mechanism of the easy-corrosion of the Pisha sandstone was revealed. High-tech materials suitable for anti-erosion and vegetation-promoting of Pisha sandstonewas developed. A Pisha sandstone dam using modified silt has been built. The field experiments were monitoredfor the effects of the anti-erosion and vegetation-promoting technology on controlling soil erosion. The results showed that: (1) The grain structureand pore cementation of Pisha sandstone leading to the high affinity of the Pisha sandstone and water; The high content of montmorillonite, calcite and feldspar and the development of pore micro-structure in the Pisha sandstone are the main reasons for the poor soil erosion resistance of the Pisha sandstone. (2) Anti-erosion and vegetation-promoting materials(W-OH) based on hydrophilic polyurethane resin combined with anti-UV stabilizer, aquasorb and vegetation growth promoter can encapsulate the Pisha sandstone particles and composethe composite with Pisha sandstone for erosion resistance and vegetation promotion, degradationcontrol freeze-thaw resistance, hydrolysis resistance and environmental friendliness. (3) The simulation analysis of materials and technology for the dam construction was carried out by using mechanics and chemical experiments. The dam design scheme and key procedures were further verified based on the field experiment, and the dam construction using modified materials of pisha sandstone was developed. The silt damusing modified Pisha sandstone was built in the Erlaohugou watershed. The dam height is 10.03 m, the controlled watershed area is 0.31 km<sup>2</sup>, and the total storage capacity is 32,600 m<sup>3</sup>. (4) According to the grading of different slopes of the Pisha sandstone and the diversity of its composition, the allocation model of the anti-erosion and vegetation-promoting treatment measures for the Pisha sandstone was proposed. In the top of the slope area, three-dimensional ecological measures such as grass, shrub and arbor mixed with intercepting ditch and other engineering measures were arranged. The technology of spraying anti-erosion and vegetation-promoting materials of low-concentration and planting vegetation measures was used on gentle slopes; the measures of spraying anti-erosion and vegetation-promoting materials of high-concentration combined with vegetation growth was adopted in steep slopes,and the consolidation material is sprayed to prevent weathering and gravity erosion of the Pisha sandstone. (5) The analysis of field plot data showed that the Anti-erosion and vegetation-promoting composite materials and the measures had obvious effects of controlling slope runoff, reducing soil erosion and vegetation restorationcompared with the bare soil plot, the runoff was reduced by more than 70%, the sediment yield was reduced by more than 90%, and the vegetation coverage was reached over 95%.</p><p> </p>

scholarly journals Numerical Modeling for Engineering Analysis and Designing of Optimum Support Systems for Headrace Tunnel

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Sajjad Hussain ◽  
Zahid Ur Rehman ◽  
Noor Mohammad ◽  
Muhammad Tahir ◽  
Khan Shahzada ◽  
...  
Keyword(s):  
Rock Mass ◽  
Support Systems ◽  
Research Work ◽  
Strength Properties ◽  
Efficient Design ◽  
Headrace Tunnel ◽  
And Performance ◽  
Selection Of

The empirical and numerical design approaches are considered very important in the viable and efficient design of support systems, stability analysis for tunnel, and underground excavations. In the present research work, the rock mass rating (RMR) and tunneling quality index (Q-system) were used as empirical methods for characterization of rock mass based on real-time geological and site geotechnical data and physical and strength properties of rock samples collected from the alignment of tunnel. The rock mass along the tunnel axis was classified into three geotechnical units (GU-1, GU-2, and GU-3). The support systems for each geotechnical unit were designed. The 2D elastoplastic finite-element method (FEM) was used for the analysis of rock mass behavior, in situ and redistribution stresses, plastic thickness around the tunnel, and performance of the design supports for the selection of optimum support system among RMR and Q supports for each geotechnical unit of tunnel. Based on results, Q support systems were found more effective for GU-1 and GU-2 as compared to RMR support systems and RMR support systems for GU-3 as compared to Q support systems.

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