不同地層比功閾值優化的統計方法及其應用

劉先珊　張同樂　牛萬保

摘要：

采用在線監測系統監測進行隨鉆參數的采樣與分析，建立了派生參數與直測參數的理論表達式，提出了多因素組合的地層比功模型，實現了地層地質條件與隨鉆參數的有機結合。以重慶市某高壓變電站施工場地為依托，建立了不同地層如素填土層、粉質粘土層、砂巖層及泥巖層的地層比功演化曲線，對比地勘信息可知，不同地層的比功值存在顯著差異。可見，合理的地層比功閾值是辨識地層類型的重要參量。運用統計學原理對勘測孔附近不同地層的比功值閾值進行保值優化，通過地勘獲得的地層信息來驗證閾值區間的可靠性。進一步采用如上地層比功閾值對該區域的其他樁位所在地層進行分析驗證，說明了地層比功閾值優化的統計方法可行，其閾值區間合理，可用于其他賦存環境的地層比功閾值確定及地層識別。

關鍵詞：

旋挖鉆機；隨鉆參數；比功模型；統計分析；閾值優化

中圖分類號：TU473.1

文獻標志碼：A文章編號：16744764（2017）02005807

Abstract：

The drilling parameters in the rotary drilling process were sampled and analyzed using online monitoring system. The theoretical expressions between the derived parameters and direct sampling parameters were constructed， and the model of formation work ratio considering multifactor combinations was also proposed to realize the perfect integration of geological conditions and drilling parameters. With the case study of a construction field of the high voltage substation in Chongqing， the curves of different formations such as backfilled soil， silty clay sandstone and mudstone formations were described and compared with the geological survey， the comparison presented obvious difference of different formations. The above results indicated that rational work ratio thresholds were significant to identify the strata characteristics. And then， the work ratio threshold of different formations was optimized near the surveying piles based on the statistical analysis theory to prove the reliability of the threshold range of different formations according to the geological information. In addition， the threshold value were used to verify the formations far away from the surveying piles， the results deeply calibrated the proposed method and verified the rationality of the threshold values. Therefore， the proposed method to determine the threshold range based on formation work ratio model can be used to another different formations and strata identification.

Keywords：

rotary drilling rig；drilling parameters；work ratio model；statistical analysis；threshold optimization

旋挖鉆機作為嵌巖樁成孔的一種重要施工方式，其鉆進過程中的隨鉆參數與地層物性特征關聯性研究不僅可以作為施工操作時的依據，還可為嵌巖持力層的判定提供基礎數據。將旋挖鉆機工作過程中的隨鉆參數進行采樣分析，并建立基于相關直測參數與派生參數的理論表達式，提出多因素組合控制的地層比功數學模型，以實現隨鉆參數判定地層物性特征的目的 [13]。……