SBIR Phase I: A Non-Destructive Method for Examining BridgeFoundations

这个小型企业创新研究第一阶段项目将开发和改进非破坏性方法，通过非破坏性和非侵入性的地震测量手段，确定桩基和钻孔的长度和数量以及桥梁地基中是否存在严重的结构缺陷。提出的测量技术有横波反射剖面法(SWRS)和环境振动法(AVS)。第二个目标将是通过实地试验来确定这些方法可能具有的任何局限性。一个已知的限制是，目前可用的任何传统方法都不能确定桩宽。在偏移数据处理步骤之后，可以从测量桩数/组的SWRS数据确定桩宽或桩径以及桩组中的桩数，桩间距和宽度/直径是可从数据获得的水平分辨率的函数，其由探测器间距和震源峰值频率的现场数据采集参数控制。具体地说，将在德克萨斯州交通部休斯敦地区休斯顿大学附近的I-45公路沿线进行横波地震反射剖面测量和环境振动测量，使用桥梁上的交通作为激励力，作为验证这两种方法的有效性和实用性的手段。德克萨斯州休斯顿区表示，他们将帮助该项目获得进入试验场和竣工施工记录的权限。联邦公路管理局估计，在接下来的20年里，必须投资1649亿美元，以解决大量的修复积压问题，并改善不断积累的桥梁缺陷。拟议研究的好处将是通过确定哪些桥梁基础是安全的，哪些需要修复，从而大大节省修复桥梁基础的费用。如此巨大的成本节约潜力将使调查系统的商业供应对系统供应商和最终用户都是有利可图的。

This Small Business Innovation Research Phase I project will develop and refine non-destructive methods by which the lengths and numbers of piles and drilled shafts and the existence of severe structural defects in bridge foundations can be determined through non-destructive and non-invasive seismic survey means. The survey techniques proposed are the shear wave reflection profiling survey (SWRS) method and the ambient vibration survey (AVS) method. A secondary objective will be to determine through field experimentation any limitations that the methods may have. A known limitation is that none of the currently available conventional methods can determine pile widths. After the migration data processing step, it is possible to determine the pile width or shaft diameter and the number of piles in a pile group from the SWRS data Measuring pile numbers/group, shaft separation and width/diameter is a function of the horizontal resolution obtainable from the data, which is controlled by the field data acquisition parameters of detector spacing and source peak frequency. Specifically, shear-wave seismic reflection profiling surveys and ambient vibration surveys will be conducted, using traffic on the bridge as the exciting force, of bridge foundations along I-45 near the University of Houston in the Houston District of the Texas Department of Transportation (TxDOT) as a means of verifying the validity and utility of both methods. The Houston District of TxDOT has indicated that they will assist the project in gaining access to the test sites and to the as-built construction records. The Federal Highway Administration estimates that over the next 20 years $164.9 billion must be invested to address the tremendous rehabilitation backlog and improve accruing bridge deficiencies. The benefits of the proposed research would be very significant cost savings in the rehabilitation of bridge foundations by identifying which bridge foundations are safe and which need rehabilitation. The potential for such significant cost savings will make the commercial availability of a survey system a profitable undertaking for both the system supplier and the end user.