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Experimental Study on Engineering Behavior of Solidified Soil for Scour Repair and Protection
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作者 WU Xiao-ni LI Ru-yu +5 位作者 SHU Jian TANG Chao CHEN Jin-jian WANG Hui-li JIANG Hai-li WANG Xiao 《China Ocean Engineering》 SCIE EI CSCD 2024年第4期625-635,共11页
A new scour countermeasure using solidified slurry for offshore foundation has been proposed recently.Fluidized solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the deve... A new scour countermeasure using solidified slurry for offshore foundation has been proposed recently.Fluidized solidified slurry is pumped to seabed area around foundation for scour protection or pumped into the developed scour holes for scour repair as the fluidized material solidifies gradually.In the pumping operation and solidification,the engineering behaviors of solidified slurry require to be considered synthetically for the reliable application in scour repair and protection of ocean engineering such as the pumpability related flow value,flow diffusion behavior related rheological property,anti-scour performance related retention rate in solidification and bearing capacity related strength property after solidification.In this study,a series of laboratory tests are conducted to investigate the effects of mix proportion(initial water content and binder content)on the flow value,rheological properties,density,retention rate of solidified slurry and unconfined compressive strength(UCS).The results reveal that the flow value increases with the water content and decreases with the binder amount.All the solidified slurry exhibits Bingham plastic behavior when the shear rate is larger than 5 s^(-1).The Bingham model has been employed to fit the rheology test results,and empirical formulas for obtaining the density,yield stress and viscosity are established,providing scientific support for the numerical assessment of flow and diffusion of solidified slurry.Retention rate of solidified slurry decreases with the water flow velocity and flow value,which means the pumpability of solidified slurry is contrary to anti-scour performance.The unconfined compressive strength after solidification reduces as the water content increases and binder content decreases.A design and application procedure of solidified soil for scour repair and protection is also proposed for engineering reference. 展开更多
关键词 scour repair and protection solidified soil PUMPABILITY STRENGTH flow properties anti-scour performance
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Effect of Plant Roots on Penetrability and Anti-Scouri-bility of Red Soil Derived from Granite 被引量:18
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作者 WUWEIDONG ZHENGSHIZHANG 《Pedosphere》 SCIE CAS CSCD 2000年第2期183-188,共6页
Distribution of plant roots in a red soil derived from granite was investigated to study the effect of plantroots on intensifying soil penetrability and anti-scouribility by the double-cutting-ring and the undisturbed... Distribution of plant roots in a red soil derived from granite was investigated to study the effect of plantroots on intensifying soil penetrability and anti-scouribility by the double-cutting-ring and the undisturbedsoil-flume methods, respectively. The plant roots system consisting mostly of fibrils, < 1 mm in diameter,was mainly distributed in the upper surface soil 30 cm in depth. It can remarhably increase the penetrabilityand anti-scouribility of the red soil derived from granite. When the root density was > 0.35 root cm-2, theintensifying effect of roots on both the penetrability and the anti-scouribility could be described by exponentequations, △ Ks = 0.0021RD1.4826 (R2 = 0.9313) and △ As = 0.0003RD1.8478 (R2 = O.9619), where △ Ks isthe value of intensified soil penetrability, a As the value of intensified soil anti-scouribility and RD the rootdensity, especially in the top soils within 30 cm in depth where plant roots were conceotrated. 展开更多
关键词 anti-scouribility GRANITE penetrability plant roots red soil
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Soil anti-scourability enhanced by herbaceous species roots in a reservoir water level fluctuation zone 被引量:3
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作者 XU Wen-xiu YANG Ling +2 位作者 BAO Yu-hai LI Jin-lin WEI Jie 《Journal of Mountain Science》 SCIE CSCD 2021年第2期392-406,共15页
Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of he... Revegetation is one of the successful approaches to soil consolidation and streambank protection in reservoir water level fluctuation zones(WLFZs).However,little research has been conducted to explore the impact of herbaceous species roots on soil anti-scourability during different growth stages and under different degrees of inundation in this zone.This study sampled two typical grasslands(Hemarthria compressa grassland and Xanthium sibiricum grassland)at two elevations(172 and 165 m a.s.l.)in the water level fluctuation zone(WLFZ)in the Three Gorges Reservoir(TGR)of China to quantify the changes in soil and root properties and their effects on soil anti-scourability.A simulated scouring experiment was conducted to test the soil anti-scourability in April and August of 2018.The results showed that the discrepancy in inundation duration and predominant herbaceous species was associated with a difference in root biomass between the two grasslands.The root weight density(RWD)values in the topsoil(0-10 cm)ranged from 7.31 to 13 mg cm^(-3) for the Hemarthria compressa grassland,while smaller values ranging from 0.48 to 8.61 mg cm^(-3) were observed for the Xanthium sibiricum grassland.In addition,the root biomass of the two herbs was significantly greater at 172 m a.s.l.than that at 165 m a.s.l.in the early recovery growth period(April).Both herbs can effectively improve the soil properties;the organic matter contents of the grasslands were 128.06%to 191.99%higher than that in the bare land(CK),while the increase in the water-stable aggregate ranged from 8.21%to 18.56%.Similarly,the topsoil antiscourability indices in both the herbaceous grasslands were larger than those in the CK.The correlation coefficients between the root length density(RLD),root surface area density(RSAD)and root volume density(RVD)of fine roots and the soil antiscourability index were 0.501,0.776 and 0.936,respectively.Moreover,the change in the soil antiscourability index was more sensitive to alternations in the RLD with diameters less than 0.5 mm.Overall,the present study showed that the perennial herbaceous(H.compressa)has great potential as a countermeasure to reduce or mitigate the impact of erosion in the WLFZ of the Three Gorges Reservoir. 展开更多
关键词 Herbaceous species root system Soil anti-scourability Water level fluctuation zone Three Gorges Reservoir
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Effect of Root Architecture on Structural Stability and Erodibility of Topsoils during Concentrated Flow in Hilly Loess Plateau 被引量:13
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作者 LI Qiang LIU Guobin +2 位作者 ZHANG Zheng TUO Dengfeng XU Mingxiang 《Chinese Geographical Science》 SCIE CSCD 2015年第6期757-764,共8页
Traditional vegetation techniques for the control of concentrated flow erosion are widely recognized, whereas only a few studies have experimentally investigated the impacts of belowground roots on the erodibility of ... Traditional vegetation techniques for the control of concentrated flow erosion are widely recognized, whereas only a few studies have experimentally investigated the impacts of belowground roots on the erodibility of topsoils in semi-arid areas. To quantify the effects of root architectures on soil erodibility and its relevant structural properties, simulated flow experiments were conducted at six-week intervals from 18 July to 20 October in 2012 in the hilly Loess Plateau. Five treatments were: 1) bare(control), 2) purple alfalfa(Medicago sativa), representing tap roots(T), 3) switchgrass(Panicum virgatum), representing fibrous roots(F), 4) purple alfalfa and switchgrass, representing both tap and fibrous roots(T + F), and 5) natural recovery(N). For each treatment, soil structural properties and root characteristics were measured at an interval of six weeks. Soil anti-scouribility was calculated. Results showed that grass planting slightly reduced soil bulk density, but increased soil aggregate content by 19.1%, 10.6%, 28.5%, and 41.2% in the treatments T, F, T + F, and N, respectively. Soil shear strength(cohesion and angle of internal friction(φ)) significantly increased after the grass was planted. As roots grew, soil cohesion increased by 115.2%–135.5%, while soil disintegration rate decreased by 39.0%–58.1% in the 21 th week compared with the recorded value in the 9th week. Meanwhile, root density and root surface area density increased by 64.0%–104.7% and 75.9%–157.1%, respectively. No significant differences in soil anti-scouribility were observed between the treatments of T and F or of T + F and N, but the treatments of T + F and N performed more effectively than T or F treatment alone in retarding concentrated flow. Soil aggregation and root surface-area density explained the observed soil anti-scouribility during concentrated flow well for the different treatments. This result proved that the restoration of natural vegetation might be the most appropriate strategy in soil reinforcement in the hilly Loess Plateau. 展开更多
关键词 fibrous roots tap roots root density soil structural properties soil anti-scouribility hilly Loess Plateau China
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Soil Anti-Scouribility Enhanced by Plant Roots 被引量:34
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作者 Zheng-ChaoZHOU Zhou-PingSHANGGUAN 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2005年第6期676-682,共7页
: The magnitude of soil anti-scouribility depends on the physical condition of the soil. Plant roots can greatly enhance soil stability and anti-erodibility. A scouring experiment of undisturbed soil was conducted to ... : The magnitude of soil anti-scouribility depends on the physical condition of the soil. Plant roots can greatly enhance soil stability and anti-erodibility. A scouring experiment of undisturbed soil was conducted to investigate the effects of roots on soil anti-scouribility and its distribution in the soil profile. At the end of each erosion test, plant roots were collected from soil samples and root surface area was calculated by means of a computer image analysis system (CIAS). Root surface area density (RSAD), the surface area of the roots per unit of soil volume, was related to soil anti-scouribility. More than 83% of root surface area was concentrated in the 0 - 30 cm soil layer. Soil anti-scouribility increased with an increase in RSAD and the value of intensified soil anti-scouribility (ΔAS) can be expressed by exponential equations, depending on the plant species. These equations were ΔAS =9.578 6 RSAD0.8321 (R2= 0.951) for afforested Pinus tabulaeformis Carr, ΔAS = 7.808 7 RSAD0.7894 (R2= 0.974) for afforested Robinia pseudoacacia L., and ΔAS= 9.256 6RSAD0.8707 (R2= 0.899) for Bothriochloa ischemum L. 展开更多
关键词 Loess Plateau root surface area ROOT soil anti-scouribility
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EFFECTIVENESS OF PLANT ROOTS TO INCREASE THE ANTI-SCOURABILITY OF SOIL ON THE LOESS PLATEAU 被引量:12
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作者 李勇 朱显谟 田积莹 《Chinese Science Bulletin》 SCIE EI CAS 1991年第24期2077-2082,共6页
The recent study results show that the intensification ability of plant roots to the anti-scourability of soil mainly depends on the distribution and twining of effective root density in the soil profile, and the phys... The recent study results show that the intensification ability of plant roots to the anti-scourability of soil mainly depends on the distribution and twining of effective root density in the soil profile, and the physical basis of effective root density is the number of 展开更多
关键词 plant ROOTS intensified value of SOIL anti-scourABILITY effect of sediment reduction effuctivenss equation the LOESS PLATEAU
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Anti-scourability of purple soil on hillslopes with different land uses 被引量:8
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作者 ZHANG Jianhui, LIU Gangcai, NI Shijun, ZHU Bo & GE Fanglong Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Resources, Chengdu 610041, China Chengdu University of Technology, Chengdu 610059, China 《Science China(Technological Sciences)》 SCIE EI CAS 2003年第z1期133-141,共9页
A large-scale flume (40 cm×10 cm×10 cm) was used to determine soil anti-scourability of 4 different land uses of purple soil in hilly areas of Sichuan, China under artificial removal of vegetation to examine... A large-scale flume (40 cm×10 cm×10 cm) was used to determine soil anti-scourability of 4 different land uses of purple soil in hilly areas of Sichuan, China under artificial removal of vegetation to examine the effects of land uses on sediment production by runoff. The results showed that soil anti-scourability declined with the increase of slope gradients in the form of power function, but there was a significant difference in the effects of slope gradients on anti-scourability between different land uses. The ratio of the mean values of soil anti-scourability was 1︰2.2︰2.5︰3.6 for forest land, new waste pasture, old waste pasture, crop land respectively, indicating that forest and grass use can significantly improve soil anti-scourability. Compared with the observations from the runoff plots located at the same sites in this region, an inconsistent result was found between anti-scourability and anti-erodibility in hilly areas of Sichuan. Essential causes of the differences in soil anti-scourability were further discussed based on analyzing the influence of inherent soil characteristics induced by different land uses on soil anti-scourability. 展开更多
关键词 SEDIMENT yield SOIL anti-scourability land use vegetation PURPLE soil.
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A PRELIMINARY STUDY ON MECHANISM OF SOIL ANTI-SCOURABILITY ON THE LOESS PLATEAU 被引量:3
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作者 李勇 朱显谟 +1 位作者 田积莹 黄义端 《Chinese Science Bulletin》 SCIE EI CAS 1990年第18期1565-1569,共5页
The resistance of soil to erosion by water can be classified into anti-washability and antiscourability. The former refers to the resistance of soil to dispersion and suspension caused by runoff, and the latter refers... The resistance of soil to erosion by water can be classified into anti-washability and antiscourability. The former refers to the resistance of soil to dispersion and suspension caused by runoff, and the latter refers to the resistance of soil to mechanical disruption and the downward pushing caused by runoff. A systematic research on soil anti-scourability, however, is still lacking. The relationships between the anti-scourability, profile structure and physical properties of the soil on the Loess Plateau have been systematically studied in this note. 展开更多
关键词 SOIL anti-scourABILITY PROFILE structure the LOESS Plateau.
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PRELIMINARY STUDY ON MECHANISM OF PLANT ROOTS TO INCREASE SOIL ANTISCOURIBILITY ON THE LOESS PLATEAU 被引量:4
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作者 李勇 徐晓琴 朱显谟 《Science China Chemistry》 SCIE EI CAS 1992年第9期1085-1092,共8页
The effects of the root system of trees, shrubs and grasses on the hydraulic andphysical properties of soil and their interrelation with increasing soil anti--scouribility byroots are quantitatively demonstrated in th... The effects of the root system of trees, shrubs and grasses on the hydraulic andphysical properties of soil and their interrelation with increasing soil anti--scouribility byroots are quantitatively demonstrated in this paper for the first time. Based on the analysisof the leading factors of roots to increase the soil anti--scouribility, a mathematical modelon increasing soil anti-scouribility by roots is established. The value in application of themodel is to explain the mechanism of roots to increase the soil anti-scouribility and toevaluate the increasing effects of soil anti-scouribility by roots in different layers of soilThe calculated results of the values in soil anti--scouribility intensified by roots at variousintensities of rainfall and slopes of the model have higher precision, all of the meanmaximum deviations between the estimated and observed values being less than 1.417 s/g. 展开更多
关键词 plant ROOTS SOIL anti-scouribility hydraulic properties of SOIL mathematical model the LOESS Plateau
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