基于Herschel-Bulkley模型的盾构隧道壁后注浆效果分析OA

To explore the influence of grout rheological properties on the backfill grouting process,a rotational viscometer was first employed to measure the rheological behavior of cement-based grouts with different ratios,analyzing the effects of various ratios on rheological parameters.Subsequently,combined with Herschel-Bulkley model and fluid simulation software,a numerical model for backfill grouting was established.Finally,the grouting process and effectiveness under the influence of factors such as location and number of grouting holes,grouting pressure,and grout ratios were investigated.The results indicate that yield stress and consistency coefficient are primarily affected by the water-binder ratio,but this influence diminishes when the water-binder ratio exceeds 0.85.The rheological index is noticeably influenced by the water-binder ratio,bentonite-water ratio,and cement-fly ash ratio,yet exhibits poor regularity.During grout filling,the top region undergoes 4 stages of evolution,whereas other regions experience only 2 stages.Positioning grouting holes near the vault can improve the filling effectiveness in the top region,and increasing the number of grouting holes accelerates the filling rate but reduces the total grout volume during the rapid growth stage.Increasing the water-binder ratio or decreasing the bentonite-water ratio reduces yield stress,thereby enhancing filling speed and volume.Increasing grout density delays early-stage filling but benefits the accumulation of total grout volume in later stages.Since excessive pressure at middle grouting holes suppresses later-stage filling speed and volume,achieving optimal filling performance requires the maximum pressure at upper grouting holes and minimum pressure at middle grouting holes.