Fluidized solidified soil(FSS)is an innovative backfill material that offers benefits such as easy pumping and straightforward construction.This study examined how varying the water-soil ratio and the curing agent dos...Fluidized solidified soil(FSS)is an innovative backfill material that offers benefits such as easy pumping and straightforward construction.This study examined how varying the water-soil ratio and the curing agent dosage affect the properties and microstructure of FSS.The strength development mechanism was investigated when composite solidification agents were used.The findings show that both the water-solid ratio and the curing agent dosage can affect the microstructure of FSS,thereby affecting its performance.When the water-solid ratio increases from 0.52 to 0.56,the unconfined compressive strength(UCS)and flexural strength of the FSS decrease by 34.1% and 39.3% after 28 d.Conversely,the curing agent dosage increasing from 10% to 30% will increase both UCS and flexural strength by 11.2 times and 11.1 times.As the curing age increases,the number of cracks at failure point in the FSS will increase and lead to a more complete failure.Numerous needle-like AFt,C-S-H gel,and C-(A)-S-H gel create a three-dimensional network by adhering to soil particles.展开更多
The cutterhead system is a core component of TBM equipment,which works in the extremely severe environment,and the strong impact loads result in severe vibration,crack,damage failure and other engineering failures.Acc...The cutterhead system is a core component of TBM equipment,which works in the extremely severe environment,and the strong impact loads result in severe vibration,crack,damage failure and other engineering failures.Accordingly,the key for cutterhead system structure design and parameter matching is to evaluate and predict cutterhead tunneling per-formance reasonably.In this paper,a prediction method for TBM cutterhead dynamic tunneling performance is pro-posed under the typical composite geological conditions,based on the CSM model of multi-cutters and cutter loads field test data.Then an actual TBM cutterhead of a water conservancy project is taken as an example,a spatial three-dimensional separation zone model for cutterhead tunneling is established under the typical geological condition,and the parameters influence rules of cutterhead tunneling performance are analyzed.The results show that,the cutter-head loads and specific energy change rules with different parameters are basically similar.Moreover,under the condi-tion of penetration p=10mm,the cutterhead bending moment coefficient of variation magnitude exceeds 20%,which is the maximum,and the normal cutter spacing optimal value is 95mm.Also,when the normal cutter spacing is kept constant in 85mm,the penetration has a greater influence on the torque and specific energy coefficient of variations,which is increased from 2mm to 10mm,and the two indexes decrease by about 73%.It is indicated that proper increase of pene-tration is beneficial to reduce the vibration fluctuation degree of torque and specific energy.The proposed method of TBM cutterhead dynamic tunneling performance and the analysis results can provide theoretical basis and design refer-ence for TBM cutterhead layout and tunneling parameters matching.展开更多
基金Funded by the China Construction Shares Technology Research and Development Project(No.CSCEC-2023-Z-07)CSCEC Strait Major Scientific and Technological Project(No.ZJHX2023C001)+1 种基金Engineering Research Center of Prevention and Control of Geological Disasters in the Mountainous Areas of Northern Fujian,Fujian Province University,China(No.WYERC2024-3)Science s of Fujian Province(No.2023J01476)。
文摘Fluidized solidified soil(FSS)is an innovative backfill material that offers benefits such as easy pumping and straightforward construction.This study examined how varying the water-soil ratio and the curing agent dosage affect the properties and microstructure of FSS.The strength development mechanism was investigated when composite solidification agents were used.The findings show that both the water-solid ratio and the curing agent dosage can affect the microstructure of FSS,thereby affecting its performance.When the water-solid ratio increases from 0.52 to 0.56,the unconfined compressive strength(UCS)and flexural strength of the FSS decrease by 34.1% and 39.3% after 28 d.Conversely,the curing agent dosage increasing from 10% to 30% will increase both UCS and flexural strength by 11.2 times and 11.1 times.As the curing age increases,the number of cracks at failure point in the FSS will increase and lead to a more complete failure.Numerous needle-like AFt,C-S-H gel,and C-(A)-S-H gel create a three-dimensional network by adhering to soil particles.
基金This work is financially supported by the National Natural Science Foundation of China(51775113)the Natural Science Foundation of Fujian Province,China(2017J01675)Scientific Research Foundation of Fujian University of Technology(GY-Z160048).
文摘The cutterhead system is a core component of TBM equipment,which works in the extremely severe environment,and the strong impact loads result in severe vibration,crack,damage failure and other engineering failures.Accordingly,the key for cutterhead system structure design and parameter matching is to evaluate and predict cutterhead tunneling per-formance reasonably.In this paper,a prediction method for TBM cutterhead dynamic tunneling performance is pro-posed under the typical composite geological conditions,based on the CSM model of multi-cutters and cutter loads field test data.Then an actual TBM cutterhead of a water conservancy project is taken as an example,a spatial three-dimensional separation zone model for cutterhead tunneling is established under the typical geological condition,and the parameters influence rules of cutterhead tunneling performance are analyzed.The results show that,the cutter-head loads and specific energy change rules with different parameters are basically similar.Moreover,under the condi-tion of penetration p=10mm,the cutterhead bending moment coefficient of variation magnitude exceeds 20%,which is the maximum,and the normal cutter spacing optimal value is 95mm.Also,when the normal cutter spacing is kept constant in 85mm,the penetration has a greater influence on the torque and specific energy coefficient of variations,which is increased from 2mm to 10mm,and the two indexes decrease by about 73%.It is indicated that proper increase of pene-tration is beneficial to reduce the vibration fluctuation degree of torque and specific energy.The proposed method of TBM cutterhead dynamic tunneling performance and the analysis results can provide theoretical basis and design refer-ence for TBM cutterhead layout and tunneling parameters matching.
