Network level pavement evaluation with 1 mm 3D survey system

The latest iteration of PaveVision3D Ultra can obtain true 1 mm resolution 3D data at full- lane coverage in all 3 directions at highway speed up to 60 mph. This paper introduces the PaveVision3D Ultra technology for rapid network level pavement survey on approximately 1280 center miles of Oklahoma interstate highways. With sophisticated automated distress analyzer （ADA） software interface, the collected 1 mm 3D data provide Oklahoma Department of Transportation （ODOT） with comprehensive solutions for automated eval- uation of pavement surface including longitudinal profile for roughness, transverse profile for rutting, predicted hydroplaning speed for safety analysis, and cracking and various surface defects for distresses. The pruned exact linear time （PELT） method, an optimal partitioning algorithm, is implemented to identify change points and dynamically deter- mine homogeneous segments so as to assist ODOT effectively using the available 1 mm 3D pavement surface condition data for decision-making. The application of 1 mm 3D laser imaging technology for network survey is unprecedented. This innovative technology allows highway agencies to access its options in using the 1 mm 3D system for its design and management purposes, particularly to meet the data needs for pavement management system （PMS）, pavement ME design and highway performance monitoring system （HPMS）.

Practical configured microtremor array measurements(MAMs)for the geological investigation of underground space

Underground space utilization is becoming increasingly essential for modern metropolitan cities such as Singapore.Mapping a soil/rock interface using traditional borehole investigation methods is expensive and difficult,owing to the numerous physical constraints within a built-up city.Boreholes are often far apart,resulting in many unforeseen ground conditions during subsequent excavation.Geophysical methods are sometimes employed as possible alternatives for fast,economical,and efficient bedrock surveys.The goal of this study is to investigate the practical details of applying microtremor array measurement(MAM)as a non-invasive surface wave survey for mapping soil/rock interfaces in Singapore.Critical configurations in field data acquisition are examined,and practical recommendations for array construction are provided.In addition,30 in situ MAM tests are carried out for two major geological formations in Singapore.From the results,a standard shear wave velocity(V_(s))of 500 m/s is found to be suitable for interpreting the soil/rock interface,for the Bukit Timah Granite and Jurong formations.However,the method does not predict well when soft Kallang formation deposits are present.Other limitations are also discussed in the later parts of this paper.Conclusions and practical recommendations are discussed,providing constructive guidance to the industry.The proposed Vs-based method and associated guidelines and limitations can be used to create a digital geological database and are especially useful for rock profiling in an urban environment.