The new high-speed, high-capacity Treviglio-Brescia railway line is an integral part of the Trans-European Transport Network, the “Mediterranean Corridor,” and constitutes a critical stage in the construction of the high-speed, high-capacity Milan-Verona railway line, which extends a total of 140 km, 27 km of which have been in operation between Milan and Treviglio since 2007. The activities currently under way include the construction of a railway line covering a distance of ~52 km between Treviglio and Brescia, and the completion of a series of complementary projects to mitigate the interference with other infrastructures (e.g., canals, underground utilities) and new road systems. Geological investigations have been necessary during the course of the work, to manage excavations and excavated materials, to manage abandoned waste encountered along the line, and for remediation of contaminated sites. In addition to the characterization of the project area, data collected have contributed to the Environmental Monitoring Plan issued by the Consorzio Eni per l’Alta Velocità (CEPAV Due), which will monitor for potential environmental impacts caused by the execution of the project, particularly related to the soil, surface water, and groundwater, and the project measures needed to reduce environmental impact. This paper provides an overview of the activities carried out so far, as illustrated with some case studies.

Using two hypothetical effusive events in the Chaîne des Puys (Auvergne, France), we tested two geographical information systems (GISs) set up to allow loss assessment during an effusive crisis. The first was a local system that drew on all immediately available data for population, land use, communications, utility and building type. The second was an experimental add-on to the Global Disaster Alert and Coordination System (GDACS) global warning system maintained by the Joint Research Centre (JRC) that draws information from open-access global data. After defining lava-flow model source terms (vent location, effusion rate, lava chemistry, temperature, crystallinity and vesicularity), we ran all available lava-flow emplacement models to produce a projection for the likelihood of impact for all pixels within the GIS. Next, inundation maps and damage reports for impacted zones were produced, with those produced by both the local system and by GDACS being in good agreement. The exercise identified several shortcomings of the systems, but also indicated that the generation of a GDACS-type global response system for effusive crises that uses rapid-response model projections for lava inundation driven by real-time satellite hotspot detection – and open-access datasets – is within the current capabilities of the community.

The geology of any particular area imposes constraints on what humans can do. These constraints are generally thought of as geologic hazards, but access to the natural resources we all use and to recreational or scenic areas, may be local issues as well. The location of roads, bridges, reservoirs, landfills and other waste-disposal sites, etc., also have both geologic and public-policy consequences.As a society, we can either plan for or fail to plan for these consequences. If we allow people to build homes in floodplains, they will become flood victims. If we prohibit building on floodplains, we have impacted the value of those lands. Whose ox gets gored, how and when? Who pays? This trip won’t offer answers to these questions, it simply will point out that these are issues that ought to be debated and that we, as geologists, can contribute technical information relevant to the debates.The field trip will travel south along the central Front Range mountain front from Marshall to the US-285 roadcut at Turkey Creek with stops to look at burning coal seams, at the differences in mineral mining between Boulder and Jefferson Counties, to reflect on mountain flooding and the possibility that Leyden Gulch could capture Coal Creek, to look at the large rocks falling off the mountain and traveling through housing, at the Red Rocks Amphitheatre as a scenic area where geology is described for the public, and at the fossil oil reservoir and roll-front uranium deposit exposed in the Dakota sands.

A reconnaissance team documented the geotechnical and geological aspects in the epicentral region of the Mw (moment magnitude) 5.8 Mineral, Virginia (USA), earthquake of 23 August 2011. Tectonically and seismically induced ground deformations, evidence of liquefaction, rock slides, river bank slumps, ground subsidence, performance of earthen dams, damage to public infrastructure and lifelines, and other effects of the earthquake were documented. This moderate earthquake provided the rare opportunity to collect data to help assess current geoengineering practices in the region, as well as to assess seismic performance of the aging infrastructure in the region. Ground failures included two marginal liquefaction sites, a river bank slump, four minor rockfalls, and a ~4-m-wide, ~12-m-long, ~0.3-m-deep subsidence on a residential property. Damage to lifelines included subsidence of the approaches for a bridge and a water main break to a heavily corroded, 5-cm-diameter valve in Mineral, Virginia. Observed damage to dams, landfills, and public-use properties included a small, shallow slide in the temporary (“working”) clay cap of the county landfill, damage to two earthen dams (one in the epicentral region and one further away near Bedford, Virginia), and substantial structural damage to two public school buildings.

Route 66 is among the most famous American highways of the middle twentieth century. A portion of the original Route 66 runs through southwestern Missouri, southeastern Kansas, and northeastern Oklahoma. This section of the road was intimately linked to the Tri-state region’s economic geology, namely mining lead and zinc as well as producing the fossil fuels—coal and natural gas—to smelt the ore. Mining began in the Tri-state district in the mid-nineteenth century and continued into the late twentieth century. An economic boom led to regional population growth and contributed to national development, but no environmental regulations existed during this period. The legacy of mining includes severe pollution, ruined communities, serious human-health issues, and devastated landscapes. Efforts now focus on protecting human health, reclamation of mined land, and remediation of water resources, led by federal and state agencies as well as universities and non-governmental organizations.

As a result of the natural setting plus poor development and management decisions, the town of North Topsail Beach on Topsail Island, North Carolina, is the state's most vulnerable barrier-island community. It is our view that this very narrow, low, and duneless island community is the most hazardous on the U.S. East Coast. Although most of North Topsail Beach was designated a CoBRA unit under the Coastal Barrier Resources Act of 1982, the area has been developed extensively (mostly post-1980), starting with “mom and pop” beach cottages, and evolving into large single-family rental houses, duplexes, and several medium- and high-rise hotels and condos. Over the years, North Topsail Beach has experienced property losses from storm surge, overwash, flooding, inlet migration, new inlet formation, and chronic shoreline erosion. The single evacuation road crosses seven swash channels and is flooded early in every significant storm. A political cauldron has evolved, often featuring the front-row property owners versus those behind the front row, in which this middle-class town seeks to solve its problems. Debate centers on beach erosion problems, including proposed beach nourishment; exemptions to banned shore hardening; and construction of a proposed terminal groin and inlet channel realignment.

Investigation and design-build construction of the Highway 20 realignment through the Oregon Coast Range provides new insight into paleo-landslides of the Tyee Formation and their slope stability. They are widespread, often extending outside of current drainage basins, and much of their morphology has been almost completely hidden by surficial processes. Radiocarbon tests indicate that some of the slide features are older than the testing limits, while other results range from approximately 18,000 to 40,000 yr B.P. The depth of erosion suggests that the paleo-slides may be as old as Pliocene.Geotechnical models of the paleo-slides, needed to analyze potential construction impacts, are developed from subsurface explorations, construction outcrops, radiocarbon testing, monitoring of geotechnical instruments, and geomorphology revealed by light detection and ranging (LIDAR). The process of predicting landslide boundaries (head scarps, toes, lateral and basal shear zones, etc.) for stability analysis of specific landslides has revealed details of their geologic evolution. This field trip provides background on (a) the investigations that have exposed numerous giant paleo-landslides, (b) findings and interpretations of the age of the landslides and (c) methods that are being employed to mitigate landslide reactivation.

Unsurfaced roads, common throughout both private and public sectors, are the source of engineering, economic, and ecological concerns. The U.S. Army currently maintains a large number of unsurfaced roads on its training and testing installations. These road networks must be maintained in a safe and serviceable condition to sustain training and testing requirements. Fort Leonard Wood’s (FLW) road network was examined to identify present problems and future engineer training requirements so that a proper maintenance plan could be recommended. Standard U.S. Army methods were used. A road management system was developed using a dynamic digital database of road conditions linked to the FLW Geographic Information System (GIS). The field data, the extent of road distresses and severity level measurements, were used to determine the unsurfaced road condition index (URCI). A repair budget was estimated for road segments with a URCI value below an established threshold. GIS analyses correlated URCI values to physical and operational conditions. Well-graded soils with a low plastic index were correlated to high URCI values. Operations data were examined to identify types of use, requested maintenance, and the resulting road condition. URCI values were higher for frequently traveled and maintained roads. Continuation of current reductions in maintenance will result in higher repair costs and possible road closures. Road rehabilitation to accommodate future traffic volume and increased vehicle loads will require proper selection of geometric design parameters, aggregate type, gradation, and layer thickness.

Engineer construction training exercises throughout Central and South America have provided U.S. soldiers with construction experience and aided the host nation by developing infrastructure. Roads, airfields, bridges, schools, hospitals, and water wells are constructed in remote areas with maximum use of local materials. Military geologists support construction by locating potential sources of aggregate, evaluating suitability of materials for road metal and fill, designing roadcuts, developing quarries, and evaluating geologic hazards that may affect the construction effort.In northern Honduras, excavation problems in a karstic limestone of the Mesozoic Yojoa Group delayed completion of a mountain road. Clay-filled solution cavities disrupted the blasting operation, jeopardizing the completion of the project. Geologists recommended rerouting the road through a rippable schist. Although longer, the new road was completed on time.In southern Honduras the lack of a suitable aggregate for a new airfield required a thorough geologic reconnaissance for new sources. Local ignimbrites were unsuitable due to their low compressive strength. Rhyolite and andesite from nearby volcanic erosional remnants were evaluated for their suitability. A quarry was subsequently developed and provided the aggregate needed to complete the project.In the Oriente of Ecuador a scarcity of suitable construction materials and unstable slopes created difficult conditions for a road and bridge construction project. Roadcuts into alternating layers of shale and limestone of the Cretaceous Lower Napo Formation created unstable slope conditions. Military geologists recommended new sources of aggregate and advised engineers on slope stability. Local construction methods were adopted to overcome these conditions.

The 1992-1993 winter storms in Murrieta, California, produced rainfall that exceeded 200% of normal. This water infiltrated into buried channels filled with up to 30 m of alluvium and thus added to rising water levels caused by accelerating urban runoff during the previous 5 yr. Downstream valleys in the California Oaks area of Murrieta, now modified to support golf courses, were little affected by the rainfall, for most of the underlying sediments had already been saturated. Upstream, however, nar-row alluvium-filled valleys were subjected to 3 to 4 m of groundwater-level rise in a 2-month period. Depending on local channel geometry and presence of fill loads, the 1992-1993 storms accelerated alluvial saturation, hydroconsolidation of collapsible soils, differential settlement, and formation of ground fissures. This combined natural and man-induced rise in regional groundwater levels damaged many houses and streets and locally impaired underground utilities. Alleged damages exceed $50 million, and litigation continues unabated. The Murrieta (California Oaks) hydroconsolidation, dif-ferential settlement, and ground fissures provide a case study of new challenges to the engineering geologist in California.

A total of 132 km of Interstate routes 8 and 10 in south central Arizona constitute a Dust Storm Alert System in which 40 remotely controlled signs with changeable messages alert motorists to blowing dust hazards. This system was installed because of a history of dust-related, multiple-vehicle accidents with abnormally high injury and fatality rates. Dust-related traffic accidents are caused primarily by locally derived dust blowing across the freeways during mesoscale dust storms spawned by cool air downdrafts from summer thunderstorms. These dust storms are most often spatially associated with abandoned, sparsely vegetated farm fields. As first installed, each battery-powered sign had two warning modes, one of which would be displayed depending on the severity of local dust conditions; each sign was controlled individually at a central console in response to reports from field personnel. An evaluation of this method of operation, mainly by questionnaire, showed that it was difficult to match the appropriate warning sign with fast-changing dust conditions, and motorists wanted better and more timely advice than the system was capable of providing. As a consequence, it was redesigned so that only one warning mode is now used, and all signs are activated at the same time. The warning mode cautions motorists and instructs them to tune to one of three commercial radio stations broadcasting special dust alert messages when the system is activated. Questionnaire responses suggest that the redesigned system is highly effective in alerting drivers to a general dust hazard condition. However, there are too many independent variables to determine statistically whether the system is responsible for a reduction in the frequency of dust accidents.

The Utiku landslide in the central part of North Island, New Zealand, is a composite failure in Pliocene siltstones, part of a regional east-northeast-trending sedimentary belt across the entire island. The Utiku slide, a small portion of a larger, ancient landslide complex, was reactivated in 1964 and has caused considerable damage to the North Island Main Trunk railway line and State Highway 1, both major transportation routes between Wellington and Auckland.The Utiku landslide is unique in that movement is almost parallel to the strike of the underlying siltstone. The lower, planar slip surface is a thin montmorillonite layer, and the principal driving force in the upper part of the slide is believed to be primarily from seepage forces developed in wide tension cracks.Several different stabilization measures are possible to reduce or eliminate movement. Although some remedial measures have been attempted and others have been recommended, the landslide continues to move, and eventually a larger portion of the ancient slide may be reactivated.

On November 7, 1972, a rockslide of approximately 13,000 m3 fell into the uncompleted northbound lane of a section of Interstate 93 in the town of Woodstock, New Hampshire. The rockslide forced almost total curtailment of construction operations at the site of the failure and necessitated a total redesign of the highway section through the rock cut.The redesign of the 44 x 213 m rock cut began with a detailed geologic mapping of the structure of the rock in the vicinity of the failure, because such a study had not been undertaken during the preliminary design phases for the project. Several weak structural trends were established for the cut area, with the most disadvantageous system striking parallel to the roadway and dipping into the open cut. This system was also troublesome because many of the joint surfaces associated with it were filled with a mylonitic material of little structural competence.A 2:1 (vertical:horizontal) slope was specified for the rock cut following this study, rather than the 8:1 slope as had been originally designed. The neatline for the presplit along this new slope was carefully placed on the mountainside to take best advantage of the existing structure of the rock mass.As excavations proceeded along this new slope, a second set of mylonitic joints was encountered on the new presplit face. Construction was again halted while this set was structurally analyzed and a second redesign for the section formulated.The second redesign was based upon the gravity-mass concept and involved the following engineering and construction: (1) excavation of a rock bench at the top of the anticipated sliding failure parallel to the newly exposed mylonite; (2) placement of a system of high-strength steel tendons into the toe of the bench to further resist the anticipated failure; (3) installation of spot rock bolts along the crest of the bench to actively secure the intact mass of the bench itself; (4) drilling of an extensive system of rock drains along the toe of the cut; and (5) installation of an instrumentation system to monitor the success of the redesign.

The geotechnics, hydrology, morphology, and vegetation of an ancient but active landslide in the lower Cuyahoga River valley, Ohio, were studied to define mechanisms contributing to failure of the slope. Engineering laboratory tests of soils showed them to be heavily overconsolidated and prone to erosion. Hydrology of the slope was monitored by periodically measuring water levels in piezometers and wells. Fluctuations in water elevations and hydraulic gradients during the observation period were correlated with precipitation data and with effective stresses. The morphology of the slope was defined in terms of recent and relict activity and was related to the vegetation and hydrology. The results of this study indicate that an interrelationship exists between the morphology, hydrology, and vegetation of the slope. Continued slope failure is caused by the unstable nature of soils and the abundance of water entering the flow system of the slope.

Multiple landsliding in both backslopes of the Interstate 45 road cut near Centerville, Texas, has been a recurrent problem since the cut was made. Landslide events can be correlated with periods of heavy rainfall. The west backslope slide moves in a downdip (southeasterly) direction, whereas the east backslope slide moves in an updip (northwesterly) direction.The road cut is primarily within the Eocene Queen City Formation, which at this locality is a fluvial deposit consisting of natural levee clay, crevasse-splay sands, and floodplain-marsh organic clay. The downdip impermeable floodplain clay retards the movement of ground water, thereby creating perched water tables and artesian conditions within the natural levee clay and crevasse-splay sand units updip. The positions of the two landslides opposite each other in the north end of the cut and within the levee clay and sand units are a direct result of stratigraphic and hydrologic conditions.In engineering terms, the highway backslopes are composed of overconsolidated, low- to high-plasticity clay and silt and poorly graded sand. Results of stability analyses, using shear-strength parameters determined from laboratory testing, indicate that initial slope failure occurred as a result of the combination of high pore-water pressure and oversteepening of the slopes. Subsequent failures have occurred because residual shear strengths are lower than initial (prefailure) shear strengths and because pore-water pressure increases during periods of heavy rainfall.

Three geologic case histories of freeway landslides in California offer significant guideposts in the sound economic planning of freeways. The three case histories are (1) San Diego Freeway, Bel Air, Los Angeles (Interstate 405; cut-slope and ancestral block glides); (2) Pomona Freeway (State Highway 60; cut slope block glides in areas previously unslid); and (3) Golden State Freeway, West Fork, Liebre Gulch (Interstate 5; fill slope in area of previous sliding).The San Diego Freeway along Sepulveda Canyon in the Bel Air area of Los Angeles has been beset with landslide problems in the Santa Monica Formation (Triassic-Jurassic) since its construction in 1961-62. Because this area is predominantly slate, proper positioning of this stretch of the freeway could have eliminated much remedial grading and redesign.A 1.6-km stretch of Pomona Freeway west of its junction with State Highway 71 has been subject to landsliding of the Puente Formation (upper Miocene) since construction. Freeway cuts had to be flattened appreciably and new rights-of-way established.The Liebre Gulch landslide along Interstate 5 occurred when road fill was placed at the head of an undetected ancestral landslide.These three case histories not only underline that the public right-of-way for freeways has not been given adequate geologic attention, but that it represents one of the most neglected opportunities in the application of geology to highway selection, design, construction, and maintenance.

One of the most important problems before this country today is the construction of highways. This condition will last just as long as 3J million miles of highways continue to be the capillaries in the transportation system in which the railways are the arteries. These highways are essential to the economic and social development of the country, and it is the duty of technical men to make every possible contribution to this work.