Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects.The high dispersion in the prope...Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects.The high dispersion in the properties of the improved material leads to designers assuming a conservative,arbitrary and unjustified strength,which is even sometimes subjected to the results of the test fields.The present paper presents an approach for prediction of the uniaxial compressive strength(UCS)of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research papers.The selected machine learning model(extremely randomized trees)relates the soil type and various parameters of the technique to the value of the compressive strength.Despite the complex mechanism that surrounds the jet grouting process,evidenced by the high dispersion and low correlation of the variables studied,the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing works.Consequently,this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.展开更多
Soft clay soils cannot usually support large lateral loads,so clay soils must be improved to increase lateral resistance.The jet grouting method is one of the methods used to improve weak soils.In this paper,a series ...Soft clay soils cannot usually support large lateral loads,so clay soils must be improved to increase lateral resistance.The jet grouting method is one of the methods used to improve weak soils.In this paper,a series of 3D finite element studies were conducted using Plaxis 3D software to investigate the lateral behavior of piled rafts in improved soft clay utilizing the jet grouting method.Parametric models were analyzed to explore the influence of the width,depth,and location of the grouted clay on the lateral resistance.Additionally,the effect of vertical loads on the lateral behavior of piled rafts in grouted clay was also investigated.The numerical results indicate that the lateral resistance increases by increasing the dimensions of the jet grouting beneath and around the piled raft.Typical increases in lateral resistance are 11.2%,65%,177%,and 35%for applying jet grouting beside the raft,below the raft,below and around the raft,and grouted strips parallel to lateral loads,respectively.It was also found that increasing the depth of grouted clay enhances lateral resistance up to a certain depth,about 6 to 10 times the pile diameter(6 to 10D).In contrast,the improvement ratio is limited beyond 10D.Furthermore,the results demonstrate that the presence of vertical loads has a significant impact on sideward resistance.展开更多
Jet grouting is a method for improving of soil and its physical characteristics.However,in this method,grouting of cement slurry with high pressure and velocity may cause damaging to soil structure,and then excavated ...Jet grouting is a method for improving of soil and its physical characteristics.However,in this method,grouting of cement slurry with high pressure and velocity may cause damaging to soil structure,and then excavated grains of soil are removed from the borehole and replaced with cement slurry.The grains,which are remained around the borehole,mixed with slurry（cement） in-situ,can create an improved mass of soil.This mass is named＂Soilcrete＂.Soilcrete mass has special characteristics such as high strength,low deformability and very low permeability.In this paper,principles of jet grouting and effective parameters have been analyzed.Then the test results obtained from Soilcrete column have been investigated.Finally,the paper concludes with presenting amount of principle jet grouting parameters at foundation of Shahriar dam according to the results of jet grouting test.Based on the measurements,the diameter,Soilcrete UCS（uniaxial compression strength）,amount of the water,grout and air pressure and lifting and rotating speed in original site of jet grouting are 1.2～1.5 m,2～3 MPa,370～390 bar,10～15 bar,6～8 bar,7～8 cm/min and 7～8 cm/min,respectively.Also it can be seen that while the column diameter falls within the upper half of the range,some values of the compressive strength are close to the lower limit of the range.展开更多
For achieving optimized jet grout parameters and W/C ratio it is concluded to set trial tests in constant local soil as the conclusion depends on local soil and presence of the extensive range of the effective paramet...For achieving optimized jet grout parameters and W/C ratio it is concluded to set trial tests in constant local soil as the conclusion depends on local soil and presence of the extensive range of the effective parameters. Considering the benefits, due to abundance of the involved variables and the intrinsic geological complexity, this system follows a great expense in the trial and implementation phases. Utilizing the soft computing methods, this paper proposes a new approach to reduce or to eliminate the cost of the trial phase. Therefore, the Adaptive Neuro Fuzzy Inference System (ANFIS) was utilized to study the possibility of anticipating the diameter of the jet grout (Soilcrete) columns on the trial phase based on the Trial and Error procedure. Data were collected from several projects and formed three sets of data. Consequently, parameters were held constant (as input) and the diameters of the Soilcrete columns were recorded (as output). To increase the precision, aforementioned data sets were combined and ten different data sets were created and studied, with all the results being assessed in two different approaches. Accordingly, Gaussian Function results in a huge number of precise and acceptable outcomes among available functions. Based on the measurements, Gaussian Function achieves the values of the R which are frequently more than 0.8 and lower values of the RMSE. Therefore, utilizing Gaussian Function, mainly a congruent relation between the R and RMSE is experienced and it leads to close proximity of the actual and predicted values of the Soilcrete diameter.展开更多
基金This work has been supported by the Conselleria de Inno-vación,Universidades,Ciencia y Sociedad Digital de la Generalitat Valenciana(CIAICO/2021/335).
文摘Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects.The high dispersion in the properties of the improved material leads to designers assuming a conservative,arbitrary and unjustified strength,which is even sometimes subjected to the results of the test fields.The present paper presents an approach for prediction of the uniaxial compressive strength(UCS)of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research papers.The selected machine learning model(extremely randomized trees)relates the soil type and various parameters of the technique to the value of the compressive strength.Despite the complex mechanism that surrounds the jet grouting process,evidenced by the high dispersion and low correlation of the variables studied,the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing works.Consequently,this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.
文摘Soft clay soils cannot usually support large lateral loads,so clay soils must be improved to increase lateral resistance.The jet grouting method is one of the methods used to improve weak soils.In this paper,a series of 3D finite element studies were conducted using Plaxis 3D software to investigate the lateral behavior of piled rafts in improved soft clay utilizing the jet grouting method.Parametric models were analyzed to explore the influence of the width,depth,and location of the grouted clay on the lateral resistance.Additionally,the effect of vertical loads on the lateral behavior of piled rafts in grouted clay was also investigated.The numerical results indicate that the lateral resistance increases by increasing the dimensions of the jet grouting beneath and around the piled raft.Typical increases in lateral resistance are 11.2%,65%,177%,and 35%for applying jet grouting beside the raft,below the raft,below and around the raft,and grouted strips parallel to lateral loads,respectively.It was also found that increasing the depth of grouted clay enhances lateral resistance up to a certain depth,about 6 to 10 times the pile diameter(6 to 10D).In contrast,the improvement ratio is limited beyond 10D.Furthermore,the results demonstrate that the presence of vertical loads has a significant impact on sideward resistance.
文摘Jet grouting is a method for improving of soil and its physical characteristics.However,in this method,grouting of cement slurry with high pressure and velocity may cause damaging to soil structure,and then excavated grains of soil are removed from the borehole and replaced with cement slurry.The grains,which are remained around the borehole,mixed with slurry（cement） in-situ,can create an improved mass of soil.This mass is named＂Soilcrete＂.Soilcrete mass has special characteristics such as high strength,low deformability and very low permeability.In this paper,principles of jet grouting and effective parameters have been analyzed.Then the test results obtained from Soilcrete column have been investigated.Finally,the paper concludes with presenting amount of principle jet grouting parameters at foundation of Shahriar dam according to the results of jet grouting test.Based on the measurements,the diameter,Soilcrete UCS（uniaxial compression strength）,amount of the water,grout and air pressure and lifting and rotating speed in original site of jet grouting are 1.2～1.5 m,2～3 MPa,370～390 bar,10～15 bar,6～8 bar,7～8 cm/min and 7～8 cm/min,respectively.Also it can be seen that while the column diameter falls within the upper half of the range,some values of the compressive strength are close to the lower limit of the range.
文摘For achieving optimized jet grout parameters and W/C ratio it is concluded to set trial tests in constant local soil as the conclusion depends on local soil and presence of the extensive range of the effective parameters. Considering the benefits, due to abundance of the involved variables and the intrinsic geological complexity, this system follows a great expense in the trial and implementation phases. Utilizing the soft computing methods, this paper proposes a new approach to reduce or to eliminate the cost of the trial phase. Therefore, the Adaptive Neuro Fuzzy Inference System (ANFIS) was utilized to study the possibility of anticipating the diameter of the jet grout (Soilcrete) columns on the trial phase based on the Trial and Error procedure. Data were collected from several projects and formed three sets of data. Consequently, parameters were held constant (as input) and the diameters of the Soilcrete columns were recorded (as output). To increase the precision, aforementioned data sets were combined and ten different data sets were created and studied, with all the results being assessed in two different approaches. Accordingly, Gaussian Function results in a huge number of precise and acceptable outcomes among available functions. Based on the measurements, Gaussian Function achieves the values of the R which are frequently more than 0.8 and lower values of the RMSE. Therefore, utilizing Gaussian Function, mainly a congruent relation between the R and RMSE is experienced and it leads to close proximity of the actual and predicted values of the Soilcrete diameter.
