Field Excavation Research Articles

Evaluating Quoddy Region archaeological site vulnerability to sea-level rise and erosion through the integration of geographic information system modeling and surveys

Modeling archaeological site erosion often depends on regional site databases that record sites accurately but with variable precision. This study examines the impact of sea-level rise (SLR) on 10 archaeological sites in the Quoddy Region of Maine through comparing models and field observations. Sites were categorized as low, mid, or high priority for field excavation based on exposure to tides. These model results were compared to field reports of site condition to evaluate the accuracy of modeling SLR as an indicator of erosion and to evaluate the application of models in developing prioritization protocols for site investigations. Models for current sea level scenarios broadly underestimate the degree of erosion reported by field observations because not all site locations were recorded at the precision required for analysis. This study emphasizes the importance of field audits for sites recorded in databases to enable large-scale modeling for the prioritization of urgently threatened sites.

Measurement and analysis of surface settlement caused by construction of quasi-rectangular shield tunnel in rich water-sand stratum.

The study is based on a section of the Zhengzhou Metro Line 8 quasi-rectangular shield tunnel. Field excavation trials were conducted to analyze the surface settlement patterns caused by the construction of a large-section quasi-rectangular shield tunnel in the rich water sand layer in Zhengzhou. Based on the characteristics of the rich water sand layer, ground settlement control measures were proposed. The research findings show that the surface settlement caused by the construction of the large-section quasi-rectangular shield tunnel in the rich water sand layer exhibits a temporal curve pattern of slow settlement (Stage I: pre-arrival of the shield), rapid settlement (Stage II: shield passage, Stage III: shield tail exiting 14.4 ~ 18m), and stable settlement (Stage IV: late settlement). In Stage I, controlling the excavation rate to maintain balance between the cutter face pressure and soil pressure is effective. In Stage II, injecting lubricating mud between the shell and the sand layer to reduce soil friction and shear slip is recommended. In Stage III, increasing the synchronous grouting volume at the shield tail and adjusting grouting pressure, as well as timely filling the shield tail construction gap, are effective methods to reduce surface settlement. The Peck formula was used to fit the transverse settlement trough on the surface, with a linear correlation coefficient R²=0.983, validating the use of the Peck formula to predict surface settlement troughs for quasi-rectangular shield tunneling in the rich water sand layer. These research findings can provide data support and reference for similar projects.

The influence of the disturbing effect of roadways through faults on the faults' stability and slip characteristics

AbstractIn order to mitigate the risk of geological disasters induced by fault activation when roadways intersect reverse faults in coal mining, this paper uses a combination of mechanical models with PFC2D software. A mechanical model is introduced to represent various fault angles, followed by a series of PFC2D loading and unloading tests to validate the model and investigate fault instability and crack propagation under different excavation rates and angles. The results show that (1) the theoretical fault model, impacted by roadway advancing, shows a linear reduction in horizontal stress at a rate of −2.01 MPa/m, while vertical stress increases linearly at 4.02 MPa/m. (2) At field excavation speeds of 2.4, 4.8, 7.2, and 9.6 m/day, the vertical loading rates for the model are 2.23, 4.47, 6.70, and 8.93 Pa/s, respectively. (3) Roadway advancement primarily causes tensile‐compressive failures in front of the roadway, with a decrease in tensile cracks as the stress rate increases. (4) An increase in the fault angle leads to denser cracking on the fault plane, with negligible cracking near the fault itself. The dominant crack orientation is approximately 90°, aligned with the vertical stress.

Variation and coordination among the plant functional traits of three coexisting shrub species in arid conditions

Functional traits are critical indicators for assessing and predicting plant environmental adaptations and survival strategies. However, less attention has been paid to root functional traits due to the costly and destructive nature of field excavations. This has resulted in a poor understanding of organ trait associations and vegetation survival strategies, particularly for plants in arid environments. In this study, we investigated 11 classical plant functional traits (leaf, stem, and root) and the intact root systems of three dominant coexisting shrubs, Calligonum mongolicum, Nitraria sphaerocarpa, and Haloxylon ammodendron, in a typical oasis–desert ecotone in northwestern China. These three coexisting shrubs generally converge on conservative resource strategies with dimorphic root systems and small leaf mass fractions to cope with strong habitat filtering and survive in arid environments. However, we found significant interspecific divergences in functional traits. Specifically, C. mongolicum had the most conserved traits, the medium root depth (370 cm), and the highest root-shoot ratio (1.72). H. ammodendron had relatively conserved traits, with the most extensive root depth (420 cm, access to groundwater) and the lowest root–shoot ratio (0.45). N. sphaerocarpa had the least conservative traits, the shallowest root depth (200 cm), and the medium root–shoot ratio (1.14). These divergences promote ecological niche segregation and ensure the stable coexistence of shrubs in this resource-limited environment. In contrast to the whole-plant economics spectrum, there was limited coordination between aboveground and belowground functional traits across the three species. Therefore, it is speculated that the different organs of these three species may operate independently to manage different constraints. The deep-rooted H. ammodendron is highly dependent on groundwater; therefore, planting them extensively in the ecotone may increase local groundwater consumption, resulting in the severe degradation of these species, particularly in the context of consecutive oasis expansion and intensified climate change. These results are expected to contribute to the development of effective ecosystem restoration and afforestation practices in such oasis–desert ecotones.

A probabilistic framework for external pitting corrosion growth modelling for buried steel pipelines considering soil properties

This paper introduces a novel framework for developing reliable probabilistic predictive corrosion growth models for buried steel pipelines using pipeline inspection data. The framework adopts a power-law function of time model formulation, accounting for nonconstant damage growth rates, and considers the correlation between defect depth and length growth models. The proposed framework explicitly incorporates local influential soil properties in the model formulation; thus, it requires no segmentation and homogenous defect growth assumption and provides defect-specific growth models. The framework is applicable regardless of the availability of matched or non-matched defect data. For corrosion initiation time estimation, two different approaches are proposed: one is to use a Poisson process to account for defect occurrence, which can also predict newly generated defects since the last inspection, and the other is to use multivariate linear regression of soil and pipe properties. The statistics of unknown model parameters are assessed using a Bayesian updating framework in which the model error can be incorporated. The proposed framework is applied using two different sets of data: one set of inline inspection (ILI) data and one set of field excavation data. A case study is conducted, where time-dependent system reliability of an in-service pipeline is assessed considering small leak and burst failure modes using the developed defect growth models. The impact of the growth model accuracy on the probability of failure is investigated, and the importance analysis is performed to identify the most influential random variables to the probability of failure.

Comparative Investigation of Axial Bearing Performance and Mechanism of Continuous Flight Auger Pile in Weathered Granitic Soils

Axial bearing performance and mechanism of continuous flight auger (CFA) pile in weathered granitic soils, i.e., a widespread special soil in South China, were investigated by field test in this study. Load–settlement responses of four CFA piles were examined, and evolutions of shaft/base resistances were captured by ultra-weak fiber Bragg gratings (UWFBG) with a reflectivity ≤−40 dB. Performances of CFA piles were compared with those of a slurry displacement (SD) pile at the same site, thirteen pretensioned spun high-strength concrete (PHC) piles in the literature and empirical data in design code. Test results show that the ultimate bearing capacity of the CFA pile is highest among different pile types, and typically is twice that of the SD pile. Again, CFA pile produces the highest shaft resistances at 140 kPa and 153 kPa in two weathered granitic soils, while the base resistance of 3080 kPa is between those of the SD pile and the PHC pile. By field excavation, the superior mechanism of the CFA pile is suggested to avoid the formation of in-between bentonite layers and prevent preferential baseflow along fissures, both of which can weaken the soil–pile interface. Overall, this study provides fundamental data through UWFBG and explanations based on field observations which underpin the need for developing a design code specified for CFA piles in South China.

Safety and reliability assessment of external corrosion defects assessment of buried pipelines—soil interface: A mechanisms and FE study

Due to local liquid accumulation (AL) in the low-lying section of the buried natural gas pipeline, external corrosion will occur at the interface between the pipeline and the soil. External corrosion will produce pit defects, which will reduce the bearing capacity of the pipeline and affect the normal operation of the pipeline. In addition, corrosion group defects can interact with each other. Thus, the service life of the pipeline is seriously affected. In this work, a case of local corrosion failure of the pipeline caused by liquid accumulation on-site is presented. The importance of this work is verified by experiment and field excavation. Besides, based on the Mises-Stress yield criterion, nonlinear analysis was carried out with the finite element method (FEM). The effects of internal pressure, corrosion pit defect size, internal and external wall corrosion, corrosion pit group, and different types of volumetric corrosion pit defects on the failure of L360QS steel pipe were analyzed with consideration of the effects of axial and circumferential zones of corrosion pits. These correlations have not been seen in previous studies. The FE results make up for the disadvantage that the corrosion is simplified to equal depth corrosion in the code, which will underestimate the residual strength of the actual corroded pipeline and lead to unnecessary repair or replacement. The results provide a reference for failure analysis and strength evaluation of buried L360QS steel pipe with corrosion defect.

GEOTECHNICAL STUDY AND CALCULATION OF THEFOUNDATION LAND FOR THE LOCATION OF RAISING CHICKENS FARM

The geotechnical study resulted from the need to know the foundation land in order to properly place the investment and includes the geotechnical exploration works performed in the site area, with the aim of providing the data necessary to solve the basic problems specifying the aspects related to: the stratification of the land on the site; physical-mechanical characteristics of existing soils; admissible pressures at different foundation levels; probable settlements; framing of field excavations; frost depth; seismic framing; hydrogeological data.

LIVESTOCK FARM LOCATION OF PIGS REPRODUCTION BASED ON THE GEOTECHNICAL STUDY

The geotechnical study resulted from the need to know the foundation land in order to properly place the investment and includes the geotechnical exploration works performed in the site area, with the aim of providing the data necessary to solve the basic problems specifying the aspects related to: the stratification of the land on the site; physical-mechanical characteristics of existing soils; admissible pressures at different foundation levels; probable settlements; framing of field excavations; frost depth; seismic framing; hydrogeological data.

Settlement base of the Neolithic banded flint mines in Krzemionki Opatowskie – an outline of the issues

The analysis of the Middle and Late Neolithic settlement pattern confirms the thesis of the significant role of the middle Kamienna river basin in the region of the Sandomierz Upland and the Iłża Forehills as the settlement base for banded flint mines in the area of Krzemionki Opatowskie. Some of the settlements of the Funnel Beaker culture located in the northern and central part of the Sandomierz Upland could be related to exploitation and processing of the: banded and the Świeciechów flint raw materials. The area of the right-bank tributaries of the Kamienna river is considered a settlement base for the prehistoric banded flint mines of the Globular Amphora culture. The surface survey and test excavation carried out in the middle course of the Kamienna river in the Iłża Forehills, as well as archaeological excavations in the mining field, showed the existence of quite numerous sites from the Neolithic and the Early Bronze Age.

Multipronged Phenotyping Approaches to Characterize Sugarcane Root Systems.

Roots are the primary conductors of water and nutrients and play a vital role in sustaining growth and yield under stressful environments. The study of plant roots poses methodological difficulties in in situ assessment and sampling, which is especially true for sugarcane (Saccharum spp.). Traditional methods during the 1920s documented the genotypic variation in sugarcane root systems, after which few studies were reported on sugarcane root traits per se until recently. In addition to morphology, rhizosphere characteristics, including allelopathic effects and/or affinity for microbial symbiosis, determine plant establishment and survival. Ultimately, root systems define the above-ground productivity of sugarcane. With the impetus for climate-resilient varieties, it is becoming more relevant to explore and utilize the variability in root system traits of sugarcane. This paper describes multipronged approaches for sugarcane root phenotyping, including field excavation by trench sampling, the use of a root core sampler, raised platforms for root sampling, and raising plants under hydroponic culture, employed by a team of scientists at the Indian Council of Agricultural Research-Sugarcane Breeding Institute (ICAR-SBI). Field excavation by trench sampling is imperative to assess the plant roots in their natural growing environment. The use of raised platforms simulating field conditions and a root core sampler are alternative approaches, with a considerable reduction in time, uniform sample size, and less loss of root material. Hydroponic plant culture allows the study of morphology, anatomical features, and rhizosphere biology, including the exudation of organic compounds and microbial interactions. Data generated from different experiments using diverse sampling methods add to the wealth of information on the root system traits of sugarcane.

SCIENTIFIC COMMUNICATION OF LVIV ARCHAEOLOGISTS ON THE EXAMPLE OF RESEARCH OF LA TÈNE AND ROMAN SITES IN THE INTERWAR PERIOD

The history of research of La Tène and Roman sites by Lviv archaeologists in the interwar period is considered. Special attention is paid to the activities of scientists of the Jan Kazimierz University of Lviv and the Shevchenko Scientific Society in this research branch. Archaeological excavations of the period carried out by the conservator Bohdan Janusz, who represented the State Group of Conservators of Prehistoric Sites, are presented separately. In particular, this refers to the excavations in Holyn' near Kalush at the settlement of the Carpathian Tumuli culture. During the Second Commonwealth of Poland, several sites were discovered and researched, including burial complexes in Hryniv, Kolokolyn, Luchka, settlements in Zalistsi, Holyn', Holigrady, and Novosilka Kostiukova, and other important sites. The works of Yaroslav Pasternak, Markiian Smishko, Tadeusz Sulimirski, Kazimierz Majewski, and other archeologists were significant at this time. Their important contribution to the development of methodology and practice of research of sites of the first centuries A.D was noted. It is concluded that in the interwar period a process of formation of modern archaeology took place. There was a large number of planned field excavations for which relevant permits from the conservator were obtained, the processing of the results became systemic, and the analysis of discovered materials was conducted with the involvement of the whole set of available methods. Most of the research results were published by the authors of the excavations, which allowed them to transfer all the results of fieldwork to descendants as much as possible. Archaeological finds from the researched sites are stored in museums of Lviv, which allows modern researchers to work with these collections.

Deformation Control Monitoring of Basement Excavation at Field Construction Site: A Case of Hydraulic Servo Steel Enhancement Geotechnology

This study presents two field cases of deep excavation using the hydraulic servo geotechnology as an enhancement to the lateral support. The first excavation process was preceded with numerical simulation to investigate the deformation of excavation pit with and without servo geotechnology. Optimised axial loading capacities from the numerical simulation were adopted at the actual excavation site. On the second excavation site, servo geotechnology was applied directly on the excavation process during actual construction without prior numerical simulation. The results showed that the servo steel support geotechnology restrained above 70% of lateral displacements of the excavated walls, and ground surface influence zone settlements were kept within the acceptable warning limits. Prior application of the numerical simulation before field excavation optimised axial loads and kept the deformation caused by excavation within project limits. The numerical simulation of servo geotechnology deformation control capacity for deep excavation projects is validated, and this study provides a practical and significant reference on similar projects.

Sharing Features in Archaeological and Crime Scene Investigations: A Comparative Methodological Analysis of Human Remains at NguvuKazi in Mang’ola, Northern Tanzania

This paper outlays preliminary archaeological investigation on human remains exhumed at Lake Eyasi basin in Mang’ola, Arusha Tanzania. The study intended to underscore the complexities of burial practices in terms of burial styles, chronological sequences of burial cairns, human remains biological profile, pathology and morphological variations. The field excavation of burial graves was carried out at the NguvuKazi, almost three kilometers southeast of Mumba rock-shelter, on the foot of Laghangereri-Ishemjega hill. The graves were tightly clustered in an area of about 60 square meters. Each grave was covered over with sizeable angular stone slabs to the height of about 50 cm above the ground surface. Buried individuals were poorly preserved and highly fragmented from geomorphological processes and anthropogenic actions. The human remains were directly placed underneath of the stones. The graves were therefore not interred so much in the ground. Corpses were buried between 20 cm and 50 cm deep and covered with piled large gneiss slabs. Such burial practices caused severe postmortem trauma leading to the deterioration, fragmentation and crumbling of human remains. Poorly preservation conditions of collected human remains and lengthy duration from the date of burial to the date of the reburial posed severe challenges as long bones were highly fragmented. These accumulated results provide primary results that may contribute significantly to crime scene detective procedures.

Durable Steel-Reinforced Concrete Structures for Marine Environments

Even in harsh marine environments, concrete structures reinforced with steel can show excellent long-term durability, with little or no reinforcement corrosion. Very few actual reinforced concrete (RC) structures have been closely scrutinized over many years and subject to interpretation using recent state-of-the-art understanding gained from detailed laboratory observations. Such a case is described for an 80-year-old RC structure observed annually over about 30 years in what is essentially an extraordinary long experiment. Despite very high chloride concentrations, field excavation evidence showed that reinforcement corrosion overall remains minimal, except where insufficient concrete compaction permitted air-voids to initiate quite severe, very localized corrosion even with still high concrete pH. It is possible that the use of blast furnace slag as aggregate may have assisted the observed durability. The case study supports other studies that show that it is possible to achieve long-term durable and therefore sustainable RC structures without additives and using only conventional reinforcement steels and conventional cements and aggregates. However, the potential dangers of deep narrow cracking extending to the reinforcement and the potentially deleterious effects of alkali–aggregate reactivity of some aggregates needs to be considered.

Coupling time-lapse ground penetrating radar surveys and infiltration experiments to characterize two types of non-uniform flow

Understanding linkages between heterogeneous soil structures and non-uniform flow is fundamental for interpreting infiltration processes and improving hydrological simulations. Here, we utilized ground-penetrating radar (GPR) as a non-invasive technique to investigate those linkages and to complement current traditional methods that are labor-intensive, invasive, and non-repeatable. We combined time-lapse GPR surveys with different types of infiltration experiments to create three-dimensional (3D) diagrams of the wetting dynamics. We carried out the GPR surveys and validated them with in situ observations, independent measurements and field excavations at two experimental sites. Those sites were selected to represent different mechanisms that generate non-uniform flow: (1) preferential water infiltration initiated by tree trunk and root systems; and (2) lateral subsurface flow due to soil layering. Results revealed links between different types of soil heterogeneity and non-uniform flow. The first experimental site provided evidence of root-induced preferential flow paths along coarse roots, emphasizing the important role of coarse roots in facilitating preferential water movement through the subsurface. The second experimental site showed that water infiltrated through the restrictive layer mainly following the plant root system. The presented approach offers a non-invasive, repeatable and accurate way to detect non-uniform flow.

The Utilization of Remote Sensing Imagery and Inverse Distance Weighted Scheme to Simulate the White Oil Effects on Soil Geotechnical Properties

This research aims to utilize a complementarity of field excavations and laboratory works with spatial analyses techniques for a highly accurate modeling of soil geotechniques properties (i.e. having lower root mean square error value for the spatial interpolation). This was conducted, for a specified area of interest, firstly by adopting spatially sufficient and well distributed samples (cores). Then, in the second step, a simulation is performed for the variations in properties when soil is contaminated with commonly used industrial material, which is white oil in our case. Cohesive (disturbed and undisturbed) soil samples were obtained from three various locations inside Baghdad University campus in AL-Jadiriya section of Baghdad, Iraq. The unified soil categorization system (USCS) was adopted and soil was categorized as clayey silt of low plasticity (CL). The cores were contaminated in a synthetically manner using two specified values of white oil (5 and 10 % of its dry weight). Then, the samples were left for three days to certify homogeneity. The results of laboratory tests were enhanced by spatial interpolation mapping, using Inverse Distance Weighted scheme for normal soil samples and those with synthetic pollution. The liquid limit rates were raised slightly as contamination rates raised, while particle size was reduced; in contrary, shear strength parameter values were decreased.

Vzorkování a jeho vliv na složení archeobotanických souborů z doby římské

The subject of the presented study is taken from a dissertation project by one of the authors who focused on the processing of archaeobotanical assemblages from the Roman Period. The main aim of the research was the reconstruction of selected aspects of the subsistence strategy of the population in the given period based on the evaluation of archaeobotanical data from various chronological and cultural contexts in a designated region, available to author. The analysed sets were obtained during field excavations primarily conducted in the last third of the 20th century and the beginning of the 21st century. Uniform methods of archaeobotanical sampling were not applied in the acquisition of these assemblages. Source information on the origin of the samples was considerably heterogeneous and, in many cases, distinctly fragmentary. This was the impulse behind the investigation into the question as to whether, and to what extent, the method of sampling affects the interpretive value of the investigated dataset and what are the limitations of the analysis of such a dataset. The principal aim of this study is not the archaeobotanical evaluation of samples, but rather to investigate a possible effect of their formal properties on the composition of archaeobotanical finds. The formal properties studied include the volume and the number of collected samples, and the spatial stratification of samples (context/feature). Intuitively, it would appear that the heterogeneous quality of this information may have a certain impact on the interpretive value of an archaeobotanical assemblage. We discuss the effect of the chosen method of sampling on the composition of macro-remains in archaeobotanical samples and assemblages with the use of statistical models.

Grounding grid corrosion detection based on mini-batch gradient descent and greedy method

To ensure the speed, recall, and precision of the algorithm to solve the algorithm’s measurement failure due to the problem of high underdetermination and the deviation of some outgoing lines from accessible nodes, the ideal resistance method is proposed to diagnose the corrosion of the grounding grid. The information extraction algorithm, a two-way heuristic network resistance diagnosis method, is added. A non-linear multi-objective optimization model of the deviation between the measured potential and the real potential is established. This paper puts forward that the grounding network’s fault diagnosis is analogous to a neural network’s training process, which makes full use of the excellent robustness and rapidity of a neural network training method. Simultaneously, the algorithm adds the retraining method combined with the field excavation in training and proves its feasibility through the Grobner basis codimension theory in algebraic geometry. Through result verification, it is found that the new algorithm can avoid the inversion failure caused by the algorithm failure due to the lack of accessible nodes and the abnormal part of input data at the same time as a fast solution.

Comparison and correlation between the laboratory, semi-theoretical and empirical methods in predicting the field excavation performance of tunnel boring machine (TBM)

Comparison and correlation between the laboratory, semi-theoretical and empirical methods in predicting the field excavation performance of tunnel boring machine (TBM)