Inclined Piezocone Penetration Aspects - Theoretical Interpretation and Experiment Verification

倾斜压电锥穿透方面——理论解释与实验验证

• 批准号: 9907951
• 负责人: Mehmet Tumay
• 金额: $ 16.23万
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-10-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9907951&HistoricalAwards=false
• 关键词: Inclined; Piezocone; Penetration; Aspects; Theoretical

***9907951TumayRapid growth and boom in surface construction and underground infrastructure inU.S. cities and suburbs increases the demand on geotechnical engineering.Geotechnical engineers are facing increasing challenges to improve in-situtesting tools for accurate site characterization of soil properties andefficient evaluation of geomedia improvement. The piezocone penetrometer test(PCPT) is a simple, fast, and repeatable test that can provide continuoussoundings of the subsurface. The PCPT test data can be effectively utilized forsoil stratigraphy and identification, and the evaluation of engineering soilproperties.The use of piezocone penetrometer for site investigation is currently limitedto vertical testing. The vertical intrusion of the cone penetrometer is notalways possible due to existing obstructions and/or lack of access. Moreover,in many cases the soil strength parameters and/or flow characteristics areneeded at an inclination plane due to the nature of soil (i.e. bedding,inclined foundation) or the alignment of reinforcing structure (i.e. soilnails, batter piles). The use of piezocone for inclined penetration has not yetbeen thoroughly investigated. The main objective of this research is to extend the application of piezoconepenetrometer by intrusion at different inclination angles, and to bring out thefundamental aspects (experimental and theoretical) of the inclined penetration.Many questions remain to be answered and interpretation methods need to bedeveloped before the inclined piezocone penetration is applied to practice. Theinfluence of the angle of inclination and soil anisotropy on the cone tipresistance, sleeve friction, generated pore pressures and their dissipationwill be investigated. The inclined piezocone penetration will be analyzed usingthe finite element methods. The outcome of this research will set the standardtowards the inclined use of the piezocone penetrometer for site investigationsin locations where it is impossible to perform vertical penetrations, andwhenever strength and consolidation parameters at a horizontal or inclineddirection are needed, as in soft ground tunneling.This research will have a significant impact toward improving subsurfaceinvestigation and introducing a new technique of inclined piezocone penetrationtesting and its interpretation to accurately evaluate soil properties forbetter design and analysis. It will also help in understanding the effect ofthe soil's inherent and induced anisotropy so that better interpretationmethods can be developed.***

*9907951 Tumay美国城市和郊区地面建设和地下基础设施的快速增长和繁荣增加了对岩土工程的需求。岩土工程师面临着越来越多的挑战，即改进现场测试工具，以准确地描述土壤特性和有效评估岩土介质的改善。压电锥渗透仪测试(PCPT)是一种简单、快速和可重复的测试，可以提供地下连续测深。PCPT测试数据可以有效地用于土壤地层和识别，以及工程土性评价。目前，压电式贯入仪在现场勘察中的使用仅限于垂直测试。由于现有的障碍物和/或缺乏通道，锥形贯入仪的垂直侵入并非总是可能的。此外，在许多情况下，由于土壤的性质(即垫层、倾斜基础)或加固结构的排列方式(即土钉、碎石桩)，土体强度参数和/或流动特性需要出现在倾斜面上。利用压电锥进行倾斜贯入尚未得到深入的研究。本研究的主要目的是扩大不同倾角下压电测深仪的应用范围，提出倾斜贯入的基本原理(实验和理论)，在将倾斜压电贯入应用于实际之前，还有许多问题需要回答，解释方法还有待发展。研究了倾角和土体各向异性对锥体阻力、套筒摩擦、产生的孔压及其消散的影响。采用有限元方法对斜压电锥侵彻问题进行了分析。这项研究的结果将为在无法进行垂直贯入的地方以及在需要水平或倾斜方向的强度和固结参数的情况下进行现场勘察制定标准。这项研究将对改进地下勘察和引入一种新的倾斜压电触探测试及其解释技术以准确评估土壤性质，以便更好地设计和分析产生重大影响。这也将有助于理解土壤固有的和诱发的各向异性的影响，从而可以开发出更好的解释方法。