Excavation Area Research Articles

Laboratory Measurement of Excavation Disturbance Effect Due to Trenchless Construction Using Distributed Fiber Optics Strain Sensing

Abstract Excavation disturbance induced by trenchless construction may lead to underground movement and deformation, which can be a potential hazard to the safety of overlying pavement structure. However, the development of a fiber optic–distributed sensing approach in recent years has provide an effective way for continuous measurement of soil strain. In this study, the mechanism of the excavation disturbance effect that is due to trenchless construction was investigated based on laboratory experiments. The sensing fibers were embedded within the overburden layer above the excavation surface to measure the distributed soil strain using Brillouin optical time-domain analysis. The relationships between ground settlements and soil strains were analyzed. The partition theory of excavation disturbance zone was verified based on test results. The influence of excavation on mechanical responses of overlying model pavement, including bending deformation and soil pressure, was measured and discussed. Laboratory test results indicated that soil strains were nearly symmetrically distributed around the excavation area, which was compressive close to the centerline and then became tensile on both sides of the excavation area. The width of the excavation disturbance zone derived from the soil strain measurements was found close to the calculation results based on the partition theory. Because of the uneven distribution of the support force that was caused by foundation settlement, the model pavement showed notable bending deformation after excavation. Therefore, the combined effects of traffic loading and excavation disturbance should be considered in the safety evaluation of trenchless construction.

Numerical Simulation Research on the Stability of Urban Underground Interchange Tunnel Group

Highway tunnel group has the characteristics of large span and small spacing, and the load distribution characteristics of surrounding rock between each tunnel section are complex. Based on geological prospecting data and numerical analysis software, the stress distribution characteristics along the characteristic section and the profile of the tunnel group were obtained. Taking Shenzhen Nanlong complex interchange tunnel group project as an example, the results show that (1) the excavation area of Qiaocheng main tunnel gradient section is large, and the grade of surrounding rock is poor, which leads to the phenomenon of large-area stress concentration on the right wall of this section. (2) The tunnels in the joint construction section of the tunnel group belong to the stress concentration area, and the influence of the right line excavation of Qiaocheng on the stability of the main tunnel of the right line of Baopeng is greater than that of the main tunnel of the left line of Baopeng. (3) The stress concentration of surrounding rock in the intersection section between the main tunnel and the ramp is caused by the too small distance between the main tunnel and the ramp of Baopeng. (4) The distance between the partitions in the K3 + 240 multiarch section of Qiaocheng is an important factor affecting the stability of the surrounding rock of the cave.

To østjyske smedjer fra middelalder og renæssance

Archaeological and archaeometallurgical investigations of two smithies in eastern Jutland – one Medieval, the other Early Modern
 Recent excavations undertaken by Vejle­Museerne have revealed remains of two smithies, one Medieval and the other Early Modern. Although the state of preservation, finds circumstances and methods of excavation were different and, in some ways, less than ideal, it proved possible to gain important and significant information from both.A farmhouse with two small outhouses was found adjacent to a substantial Medieval settlement at Kristinebjerg Øst, located southwest of Fredericia, between Taulov and Erritsø. The farm’s main house, which measured c. 26 x 6 m and was dated to c. AD 1250-1350, appeared to be located separately from the main settlement. The building contained clear traces of a smithy in its eastern part, and the working space was estimated to have been about 6 x 6 m. Numerous plano-convex pieces of slag were found, together with some iron objects. SEM analysis of the slag suggests that they represent the primary smithing of local iron blooms, and the smithy has even been interpreted as a specialist forge with the sole function of refining impure domestic iron. No iron bloomery slags or furnaces were, however, found adjacent to the smithy or within the entire excavation area. The term “local iron” must therefore be viewed in a larger perspective, i.e. derived from the northern and eastern parts of Jutland. (figs. 1-4)Traces of Medieval and Early Modern houses, two wells, some refuse pits and refuse layers were found in the village of Stouby, between Vejle and Juelsminde. Remains of a smithy were found, although the excavation was limited by an existing paved path, and it was therefore not possible to uncover the entire building. The smithy was 14C (AMS) dated to AD 1486-1573, while an adjacent refuse pit, A242, gave three rather different dates, namely AD 1415-1435, 1474-1521 and 1648-1664. The postholes of the smithy, A1, contained a large amount of hammerscale, both flat and spheroidal. Refuse pits, refuse layers and a well adjacent to the smithy contained a large number of plano-convex pieces of slag, as well as a smaller quantity of iron bars and debris. The content of soil samples from postholes and a refuse layer in the smithy, together with SEM EDX analysis of the slag, showed that refining of domestic iron, presumably from Jutland, had taken place, as well as hammer welding. Iron bars and nails ranged vastly in quality, from phosphorous-rich impure iron to iron of a better quality containing 0.1-0.2% carbon. None of the analysed pieces of iron were of domestic origin. They were mostly from Sweden or Norway, but a single iron bar may have originated from the Waloon area (Belgium). Mineral coal was also unexpectedly found in a refuse pit, A242, directly adjacent to the smithy. Coal is, by its very nature, an import in Denmark, and early archaeological evidence and mentions of it in the written sources are scarce in the 16th century. The Crown appears to have been ordering coal for use in the royal smithies by the late 1560s, and vast, regular imports from Germany and Britain are evident from the late 16th century onwards. The coal recovered from a refuse pit dated to the late 15th or early 16th century must therefore be considered quite an early find. The somewhat uncertain dating of the refuse pit could, however, render the find less significant (figs. 5-25).Excavations of Medieval and Early Modern smithies are quite rare occurrences in Denmark, but the preliminary results appear to suggest a tendency towards larger smithies, relative to those of the Iron Age and Viking Age. The data are, however, still too scant to enable secure validation of this theory. What the data do seem to confirm is that, from the 12th to the late 16th century, refining of impure, domestic iron blooms has been undertaken as one of the everyday tasks of a blacksmith, even if some almost pure, imported iron bars were also available. It has even been suggested that there is evidence of superficial carburisation or even case carburisation, but this must presently be viewed with scepticism. The investigations of the two smithies seem to prove that valid data and important information on the blacksmith’s craft can be gathered, even when the circumstances are far from ideal. If sufficient archaeometallurgical analyses are undertaken, smithies seem almost invariably to yield significant knowledge on the history of technology.

Presenting Shape Memory Polymers SMP and some Reinforcement materials for the Consolidation of Gaps in Archaeological Bones

Mummies and bones are potentially materials since they retain the memories of the ancients and revealed the degree of their greatness. Bones are organic materials that include proteins like collagen, minerals including calcium hydroxyapatite, as well as other substances. By assisting with other factors (physical or chemical), the essence of bone allows microorganisms as well as insects to assault it. The aspects that can be formed as a result of this degradation process are known as holes. Gaps are also a challenging task for bone artifacts, especially in the excavation area. This current article review focused on the factors that create holes. In addition to the survey about the shape memory polymers aerogels (SMPA) and reinforcement materials which can be utilized to adapt to the old bones, as well as improvement materials to render certain old reinforced polymers provide shape memory behavior. The examination and investigation analysis tools which could be utilized for evaluating the treated bones with certain shape memory polymers aerogels were also addressed in the article review.

Spina revisited: the 2008 geophysical prospection in the light of the excavation results

In 2008 the British School at Rome (BSR) and Archaeological Prospection Services of Southampton (APSS) conducted a geophysical survey at the Etruscan site of Spina (Comacchio, Emilia Romagna) on the behalf of the University of Southampton, the University of Zurich and the Soprintendenza Archeologia, Belle Arti e Paesaggio per la Città Metropolitana di Bologna e le Province di Modena, Reggio Emilia e Ferrara. The survey was conducted during a period of excavations in a central area of the site and aimed to place the excavation results in a wider context. This paper re-examines the geophysical survey results ahead of a new programme of research being led by the University of Bologna.

Influence of Hollow Effect on PPV of Wall Rock under Blasting Load

The purpose of writing this thesis is to solve the problem that the hollow effect of blasting construction affects the PPV of tunnel wall rock. Based on the law of energy attenuation and seismic wave propagation, the calculation equation of PPV of wall rock in excavation area and no-excavation area under blasting load is derived, and the variation law of PPV of wall rock under different loads is calculated by FLAC3D software. The results show that: (1) The accuracy of the calculation equation is verified by the calculation results of the software; the error between those is less than 6%; (2) In the range of twice the distance from the Heading Face, the hollow effect of wall rock is directly proportional to the load value; (3) The blasting load of 0.8MPa makes the maximum void effect concentrated in the wall rock 8m away from the face. The difference of PPV between the excavated area and the uncut area caused by void effect is 2.23 cm/s, and the quotient is 1.21 times.

ANALYSIS OF MAINGATES STABILITY IN STEP COAL SEAMS DURING PROTECTION BY COAL PILLARS

The purpose of the work. Studying the stability of haulage drifts of steep coal seams with the method of protecting coal by pillars. An integrated approach was used as research methods, including: a full-scale experiment, analytical studies, interpretation of the results obtained. To assess the durability of mine workings, full-scale experiments were carried out to study the manifestations of rock pressure in the haulage drifts with the method of protecting coal by pillars, when the magnitude of the change in the cross-sectional area and the convergence of side rocks on the contour of the development workings along the length of the excavation section was established. It is fixed that at the maximum relative deformation of coal pillars (ε ≈ 0,7), the loss of the cross-sectional area of the haulage drifts at a distance of l ≥ 60 m behind the working face is more than 50 %, which does not correspond to the operational state of the workings. When studying the deformation properties of protective structures, it was found that after their deformation by 10–20 %, an increase in the convergence of side rocks in the haulage drifts begins, a distortion of the shape and loss of the bearing capacity of coal pillars. The distortion of the shape of the security structures contributes to the intensification of the displacements of the roof on the contour and is accompanied by a deterioration in the durability of the haulage drifts in the excavation areas of the coal mine. It has been proved that on a steep drop, with the method of protecting the haulage drifts with coal pillars, the change in the cross-sectional area of the excavation occurs along a linear relationship with an increase in the length of the excavation section due to the distortion of the shape and loss of the bearing capacity of the security structures. To improve the safety of miners in the excavation areas of coal mines developed steeply falling coal seams, it is recommended to abandon the method of protecting the haulage drifts with coal pillars. To avoid emergencies associated with the collapse of the roof, it seems advisable to use purposeless methods of protection – flexible structures or backfilling of the goaf.

ASSESSING THE CHRONOSTRATIGRAPHY OF EL MIRÓN CAVE, CANTABRIAN SPAIN

ABSTRACTEl Mirón is an important archaeological cave site in Cantabria (Spain) with a stratigraphy covering the late Middle Paleolithic to the Modern Period. The Magdalenian levels are especially rich in artifacts, faunal remains, and features, and included the burial of an adult female (“the Red Lady”), as well as other scattered human remains, while the Neolithic levels contained the oldest combined evidence of ceramics, domesticated grain and livestock in the region. However, in the absence of diagnostic artifacts in many levels that would always provide a traditional cultural chronology, radiocarbon dating has been essential in understanding the temporal framework for human activity at the site. Over the duration of more than two decades, the El Mirón Project has therefore obtained 93 radiocarbon dates, which cover the entire stratigraphic record as found in several different excavation areas. In light of the considerable methodological advances that radiocarbon dating has seen since 1996 we aim to evaluate the reliability of the published 14C record for El Mirón Cave, and to improve the accuracy of the radiocarbon based chronostratigraphy through Bayesian modeling. The results shed light on which dates may be used for future research and where dating discrepancies reflect taphonomic processes, thereby advancing intra-site and regional archaeological comparisons.

Rediscovering Geula Cave: A Middle Paleolithic cave site in northern Mt. Carmel, Israel

This paper focuses on new findings from Middle Paleolithic Geula Cave, Israel, located in the northern part of Mt. Carmel. The cave, consists of several small chambers that are remnants of a larger cave system, initially excavated between 1958 and 1964. The occupation at the cave was ascribed to Middle Paleolithic modern humans.In 2016, a salvage excavation was conducted in areas of the cave that were not previously explored. Analyses of the new excavation revealed a consistency in lithic technology throughout the new excavation areas, with an emphasis on Levallois production using mainly bidirectional and centripetal core preparation modes. The faunal study identified intensive hyena and porcupine activities in small chambers, probably at the back part of the cave, while fractured bones in association with flint artifacts were found at what appears as the living area in the cave. Luminescence ages indicated that Geula Cave was occupied as early as 175 ka, but that the major occupation was from 120 to 100 ka.The major occupation at Geula chronologically overlaps with the Skhul and Qafzeh Caves thus reinforcing the notion that Homo sapiens dominated the southern Levant during early MIS 5. This study demonstrates the importance of reinvestigating and reevaluating past excavated prehistoric sites and their contents to enhance our understanding of the regional, cultural and biological history.

NO-TILL TECHNOLOGY AS A FACTOR OF ACTIVITY OF SOIL INVERTEBRATE IN AGRICULTURAL CHERNOZEMS OF STAVROPOL REGION

Soil macro- and mesofauna is highly sensitive to various methods of agricultural cultivation, therefore soil invertebrates are used as bioindicators of agrocenoses ecological condition. Since the macro- and mesofauna to a largely extent control the water balance of the soil and participate in the formation of humus, special attention should be paid to soil fauna in arid regions, primarily in the Cernozem Region. In this work, for the first time, an integrated estimation of the population density and ecological and functional diversity of macro- and mesofauna of Vorony-Calcic Chernozem in the Stavropol region is given. The possibility of using these groups of invertebrates as bioindicators of the ecological status of agrocenoses has been shown. It is proved that the use of no-till technology stimulates the activity and number of all groups of macro- and mesofauna. The purpose of the work is to estimate the numbers and taxonomic diversity of ecological and functional groups of macro- and mesofauna with various technologies of soil cultivation (traditional plowing and no-till) with and without mineral fertilizers on the agrochernozems of the Stavropol region. Experiments on research no-till technology were carried out in 2012-2019 in an experimental farm of the North Caucasus Federal Scientific Agrarian Center (Shpakovsky district of the Stavropol region). In 2019 we studied plots of fields with three types of factors: tillage (plowing and no-till technology); presence/absence of fertilizers; agricultural crops. The soil is Vorony-Calcic Chernozem. Crop rotation: maize (Zea mays L.) variety Mashuk, soybean (Glycine max L.) variety Duniza (until 2018), which was replaced later by peas (Pisum sativum L.) variety Phaeton, winter wheat (Triticum aestivum L.) variety Deya, sunflower (Helianthus annuus L.) variety Bagrat. Deposit soil near the experimental fields served as a control. Fertilizers were applied at the time of sowing (N160P90K60 for winter wheat, N72P58K32 for sunflower, N80P48K48 for corn, and N60P60K60 for soybeans and peas). The soil macrofauna was registered by the method of excavation of areas 25×25×30 cm and manual analysis of soil samples. Soil mesofauna was isolated from the soil monolith by the method of eklectors, identified and counted using a microscope Biomed-5 PR LUM (Russia) at a magnification of ×40. Most abundant among the macrofauna were centipedes (Myriapoda), adults and larvae of coleopterans (Coleoptera), spiders (Araneae) and earthworms (Lumbricidae). Aporrectodea caliginosa dominated among earthworms, while single of A. roseawere found only in deposit lands. The minimum number of A. caliginosa (32 ind/m2) was recorded under peas and sunflower with traditional plowing, the maximum — under corn on no-till plots and on plowed plots (556 and 512 ind/m2, respectively). In general, the number of earthworms was higher in no-till fields under all crops (excluding sunflower) in comparison with plowed plots. Among other groups of soil macrofauna, the most numerous were centipedes (up to 1500 ind/m2), as well as spiders (up to 500 ind/m2) and beetles (up to 500 ind/m2). Woodlice (Oniscidea) and molluscs (Gastropoda) were also encountered. The density of centipedes, spiders, coleoptera and earthworms was always higher for no-till options than for plowed fields, regardless of crop. The application of mineral fertilizers, as a rule, reduced the number and diversity of the macrofauna representatives. Among the mesofauna, ticks (Acari) and collembolans (Collembola) prevailed in terms of abundance and diversity. Mesofauna of no-till fields was taxonomically more diverse than plowed plots. The minimum number of mesofauna representative was found under peas and corn, the maximum — under winter wheat and sunflower. In general, the distribution of soil invertebrates (macro- and mesofauna) was significantly influenced by the method of soil cultivation, however, the agricultural culture often influenced the abundance indicators. The use of fertilizers reduced the biodiversity of macrofauna and decreased its number in all plots, regardless of the method of soil cultivation.

ТЕХНОЛОГИЯ NO-TILL КАК ФАКТОР АКТИВНОСТИ ПОЧВЕННЫХ БЕСПОЗВОНОЧНЫХ В АГРОЧЕРНОЗЕМАХ СТАВРОПОЛЬСКОГО КРАЯ

Soil macro- and mesofauna is highly sensitive to various methods of agricultural cultivation, therefore soil invertebrates are used as bioindicators of agrocenoses ecological condition. Since the macro- and mesofauna to a largely extent control the water balance of the soil and participate in the formation of humus, special attention should be paid to soil fauna in arid regions, primarily in the Cernozem Region. In this work, for the first time, an integrated estimation of the population density and ecological and functional diversity of macro- and mesofauna of Vorony-Calcic Chernozem in the Stavropol region is given. The possibility of using these groups of invertebrates as bioindicators of the ecological status of agrocenoses has been shown. It is proved that the use of no-till technology stimulates the activity and number of all groups of macro- and mesofauna. The purpose of the work is to estimate the numbers and taxonomic diversity of ecological and functional groups of macro- and mesofauna with various technologies of soil cultivation (traditional plowing and no-till) with and without mineral fertilizers on the agrochernozems of the Stavropol region. Experiments on research no-till technology were carried out in 2012-2019 in an experimental farm of the North Caucasus Federal Scientific Agrarian Center (Shpakovsky district of the Stavropol region). In 2019 we studied plots of fields with three types of factors: tillage (plowing and no-till technology); presence/absence of fertilizers; agricultural crops. The soil is Vorony-Calcic Chernozem. Crop rotation: maize (Zea mays L.) variety Mashuk, soybean (Glycine max L.) variety Duniza (until 2018), which was replaced later by peas (Pisum sativum L.) variety Phaeton, winter wheat (Triticum aestivum L.) variety Deya, sunflower (Helianthus annuus L.) variety Bagrat. Deposit soil near the experimental fields served as a control. Fertilizers were applied at the time of sowing (N160P90K60 for winter wheat, N72P58K32 for sunflower, N80P48K48 for corn, and N60P60K60 for soybeans and peas). The soil macrofauna was registered by the method of excavation of areas 25×25×30 cm and manual analysis of soil samples. Soil mesofauna was isolated from the soil monolith by the method of eklectors, identified and counted using a microscope Biomed-5 PR LUM (Russia) at a magnification of ×40. Most abundant among the macrofauna were centipedes (Myriapoda), adults and larvae of coleopterans (Coleoptera), spiders (Araneae) and earthworms (Lumbricidae). Aporrectodea caliginosa dominated among earthworms, while single of A. roseawere found only in deposit lands. The minimum number of A. caliginosa (32 ind/m2) was recorded under peas and sunflower with traditional plowing, the maximum — under corn on no-till plots and on plowed plots (556 and 512 ind/m2, respectively). In general, the number of earthworms was higher in no-till fields under all crops (excluding sunflower) in comparison with plowed plots. Among other groups of soil macrofauna, the most numerous were centipedes (up to 1500 ind/m2), as well as spiders (up to 500 ind/m2) and beetles (up to 500 ind/m2). Woodlice (Oniscidea) and molluscs (Gastropoda) were also encountered. The density of centipedes, spiders, coleoptera and earthworms was always higher for no-till options than for plowed fields, regardless of crop. The application of mineral fertilizers, as a rule, reduced the number and diversity of the macrofauna representatives. Among the mesofauna, ticks (Acari) and collembolans (Collembola) prevailed in terms of abundance and diversity. Mesofauna of no-till fields was taxonomically more diverse than plowed plots. The minimum number of mesofauna representative was found under peas and corn, the maximum — under winter wheat and sunflower. In general, the distribution of soil invertebrates (macro- and mesofauna) was significantly influenced by the method of soil cultivation, however, the agricultural culture often influenced the abundance indicators. The use of fertilizers reduced the biodiversity of macrofauna and decreased its number in all plots, regardless of the method of soil cultivation.

The effect on land-use changes on water availability in the Cidongkol Irrigation Area

The city of Tasikmalaya has now changed, especially in the field of infrastructure. The impact of infrastructure development affects uncontrolled land-use change. One of the transportation infrastructure built by the City of Tasikmalaya Government is Mangin Road. Paddy fields that meet the area gradually began to become settlements. Transfer of land functions in the area, resulting in reduced paddy fields. The Cidongkol Irrigation Area currently has a 116 ha rice field area from an initial 192 ha area. The purpose of this study was to determine the fulfilment of the rice field area and to be associated with previous research. The data processing method is analyzing the availability that comes from Cikalang Channel and water needs. In the initial condition, the required discharge of about 92% was not fulfilled. Whereas with an area of 116 ha of rice fields, around 92% was not met. Cikalang Channel serves 246 ha of paddy fields. With conditions like this, Cikalang Channel is not able to serve the entire area. To meet water needs, farmers use modified cropping patterns. The City Government of Tasikmalaya has managed the excavation area, and part of the land has been replanted to restore its function.

Impact of Construction Method and Ground Composition on Headrace Tunnel Stability in the Neelum–Jhelum Hydroelectric Project: A Case Study Review from Pakistan

During underground construction, the behavior of the ground is influenced by characteristics of the rock mass with situ stresses and ground water, cross section of the excavation area, excavation method, and the rate of excavation. These fundamental features are considered to ensure the support and stability of underground excavations and achieve long-term successful operation. However, the ground composition of the Himalayas hinders tunnel excavation, especially in case of mechanized tunneling; this causes time and cost overruns. This study has reviewed the recently completed Neelum–Jhelum Hydroelectric Project; the project complexities, geological environments involving significant overburden and tectonic stresses, and effects of the excavation method on tunnel stability were analyzed. The major challenges that were encountered during construction are discussed herein along with their countermeasures. An analysis of project-related data reveals that latest techniques and approaches considering rock mechanics were used to complete the project; the existing approaches and methods were accordingly verified and extended. Apart from ground composition, the excavation methods used play an important role in the occurrence of severe rock bursts. Thus, the findings of this study are expected to be helpful for future tunneling projects in the Himalayas.

A Reassessment of the Chronology of the Iron Age site of Khirbet en-Nahas, Southern Jordan

ABSTRACT The chronology of Khirbet en-Nahas, a large Iron Age archaeological site located in the copper mining region of Faynan, southern Jordan, has been under fierce debate for the last 15 years. Since the site was excavated in 2002–2009, several analyses challenged the excavators’ interpretation of the stratigraphy, the results of the radiocarbon data and its dating. However, so far none of these challenges considered the final report published in 2014, which provided precious information from new areas of excavations and novel series of 14C dates. It is therefore necessary to have an independent reassessment of the archaeological and radiocarbon evidence of each excavated area based on the final report. Reasonable questions raised since the beginning about the 14C dates and the use of Bayesian modelling, the stratigraphic contexts from which they were recovered, and the interpretation of the ceramic assemblage can now be reassessed through a meticulous analysis of the site’s stratigraphy and finds. Considering this re-evaluation of the evidence, it is possible to present a reconstruction of the history of the site somewhat different from the one suggested by the excavators.

A challenging archaeo-geophysical exploration through GPR and ERT surveys on the Keber Tepe, City Hill of Doliche, Commagene (Gaziantep, SE Turkey)

Doliche is an ancient city located at the northern fringe of Gaziantep in SE Turkey. The settlement spreads over a shallow hill called Keber Tepe. However, the lack of visible remains on the surface severely limits the comprehension of the spatial organization of the site. To understand the ancient city layout, but also to identify promising starting points of archaeological investigations, geophysical exploration plays a substantial role. In 2019 and 2020 campaigns, ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) surveys were conducted to determine anthropogenic structures in selected three study areas (SA) of the hill. Among them, SA-1 is adjacent to an excavation area on the south slope of the hill, where a large three-aisled Christian basilica had been discovered. SA-2 is in the eastern part of the city area, next to a sizeable civic bath building of the Roman period. Lastly, SA-3 covers the mosaic floor of the central nave and the terrace of the basilica where archaeological excavations were carried out in 2020 compaign. Archaeo-geophysical survey presented a challenging task as Keber Tepe is mainly composed of clayish-limestone and the same material had been used for architectural construction. Despite the disadvantages, GPR provided partial traces of the nave walls conforming with the existing basilica structures. The archaeological trenchs conducted in SA-3 confirm the partial reflection properties observed in the GPR sections. ERT surveys in this area provided subsurface models containing traces of anthropogenic structures unearthed. Since the findings obtained from both methods support each other very well in SA-2, we assumed that the field condition in this region of the hill is different or buried materials have lesser clay content in comparison to SA-1 and SA-3. As a result, the archaeo-geophysical survey contributed to the understanding of the archaeological structures and help to identify promising areas for further archaeological excavations.

Analysis of the circumstances of methane explosions at the mines of Ukraine

The article analyzes and summarizes the circumstances of methane explosions in mines of Ukraine over the past 50 years, which occurred as a result of the formation of dangerous methane concentrations in the outgoing jets of mining areas. Both explosions in excavation areas and explosions associated with gas contamination of areas that occurred outside of them were reflected. The typification of methane explosions is carried out and the schemes of their occurrence are determined, the classification of which is based on the causes of the formation of an explosive atmosphere. These include explosions: in mined-out areas, in case of ventilation disturbances, in local accumulations of methane, in the degassing of areas after ventilation disturbances, in the degassing of dead-end workings within excavation areas, with increased gas release, as well as explosions caused by gas contamination of excavation areas that arose behind their limits. It has been established that the main reasons for the formation of an explosive atmosphere in mining areas during methane explosions are disturbances in ventilation, accumulation of methane in mined-out areas and the formation of local accumulations. Data on the most serious accidents from methane explosions in the history of the coal industry in Ukraine are given separately. It is concluded that stationary automatic equipment for monitoring the concentration of methane does not always make it possible to recognize a hazardous situation in mining areas in case of disturbances in ventilation and due to other causes of gas pollution. Several other gas-dynamic phenomena that have occurred in recent years have also been analyzed; these include endogenous fires from spontaneous combustion of coal during mining operations in an extremely stressed coal-rock mass. As recommendations, it was noted that to improve the efficiency of air-gas control and reduce the likelihood of methane explosions, the following measures are advisable: control of air consumption in mining areas of mines of category III for methane and higher, monitoring of carbon monoxide in the initial ventilation jets of mining areas during the development of coal seams prone to spontaneous combustion, improving the organization of notification of underground personnel about cases of gas contamination of mine workings. Keywords: coal mines, mining areas, methane, explosions, endogenous fires.

Analysis of electric consumption: a study in the excavation area of the modern coal mine

The growth in the power supply of coal mines over the past decades has had a significant impact on their power consumption. The use of outdated materials for assessing the coal mine energy characteristics may lead to large calculation errors. At the same time, the problem of reducing the energy intensity of coal mining does not lose its relevance. However, in order to achieve it, it is necessary to take into account the current level of development of the mechanized complex of excavation areas. The widespread introduction of SCADA systems and the development of methods for big data processing makes it possible to collect large arrays of measurements and study the power consumption of mining equipment. In this paper, on the basis of extensive arrays of electrical load measurements and technological parameters, a statistical analysis of the load of a modern Eickhoff SL 900 longwall shearer of the Kuzbass coal mine is carried out.

Лахути IV – новая стоянка раннего палеолита в долине реки Оби-Мазар (Южный Таджикистан)

The article presents the results of a joint Russian-Tajik geoarchaeological expedition in the middle reaches of the Obi-Mazar River (Republic of Tajikistan). During 2021 fieldwork two Tajikistan Loess Palaeolithic sites were studied: Kuldara (14 pedocomplexes) and Obi-Mazar (7 pedocomplexes). A significant amount of palaeogeographic work was carried out at both sites including sampling for a wide range of geological analyses. At Kuldara, five excavation trenches were established and a small amount of artifacts from pedocomplexes 4 and 5 as well as a few items from PC’s 10 and 11 were collected. Lakhuti IV corresponding to PC 5 was found between the known sites of Obi-Mazar-6 and Lakhuti I. The excavation area was 6 m2 and 2.2 m deep. Archaeological material (662 specimens) was deposited at 8 levels, but can be regarded a single industry. The primary reduction is based on several simple flaking techniques — radial flaking from a single surface, citron and parallel flaking. Some cores were prepared on large and thick spalls; the ventral surface was used as a prepared flaking surface. “Citron flakes” were also found (~ 8 % of the total number of flakes). Not a single blade was discovered. The complex contains roughly equal proportions of scrapers on large spalls, notched-denticulate tools and unifaces. According to the available set of geological data for the Obi-Mazar Valley, PC 5 is dated to ca. 0.5 Ma. The Lahuti IV materials have parallels in the synchronous Early Palaeolithic industries of Tajikistan. A distinctive feature of this site is a very high concentration of artifacts and their occurrence in well-defined cultural horizons, which is recorded for the first time at Loessic Palaeolithic sites.

Optimum design of multi-anchored larssen type sheet pile wall for temporary construction works

In some construction works such as multi-basement buildings, subways, deep excavation problems are encountered. In such cases, the shoring walls are used to to prevent damage to the structures next to the excavation area and to provide a safe working environment in the excavation area. In cases where a temporary excavation support is required, sheet pile walls can be more economical comparing to the other walls in the long run due to their reusability. In the present study the analyses were carried out by changing various parametric components such as the number of anchors in vertical row, horizontal and vertical spacing amongst the anchors, anchor angle and excavation depth in LARSSEN type sheet piles constructed temporarily in medium-dense sand. In the analyses, the trapezoidal horizontal earth pressure envelope recommended by FHWA (1999) since the stress concentration occured at the anchor locations. Besides the limit values recommended by FHWA (1999) and BS (1989) was used in the analyses. In total 35488 different sheet pile wall geometry configurations were investigated. According to research results, the lowest costs occur when the horizontal spacing amongst the anchors is 3 m and the angle of the anchors with the horizontal is 150. The lowest costs were obtained when the vertical distance of the uppermost anchor to the ground surface is 3 m. Sheet pile sections with optimum cost were modeled in Plaxis 2D to run displacement analyses. Findings showed that the wall displacements were within the allowable limits commonly used in the literature.

The New Swedish Cyprus Expedition 2020 (The Söderberg Expedition): Excavations in the cemetery of Hala Sultan Tekke

In autumn 2020, the 11th season of excavations at the Late Bronze Age city of Hala Sultan Tekke took place in extramural Area A, where, based on indications provided by magnetometer surveys, tombs, possible ritual pits, and numerous wells were found, but no architectural remains. Tomb RR, which had been partly exposed in 2018 and 2019, was further excavated. It revealed a preliminary minimum total of 54 individuals (MNI) and numerous artefacts including, inter alia, complete ceramic vessels, figurines, jewellery, ivory objects, a scarab and a cylinder seal. The life span of the tomb can, on the evidence to date, be assigned from the LC IIA1 to LC IIC1 period, i.e., roughly from the last quarter of the 15th to the end of the 14th or the beginning of the 13th century BCE. Just to the south of Tomb RR another magnetic anomaly, Tomb SS, was investigated. Only the uppermost burial layer was reached, which was covered by two large deposits of several hundred intact or fully restorable ceramic vessels. These include various types of Cypriot tableware, as well as imports from the Aegean, Anatolia and the Levant. The preliminary date of these contexts is LC IIA˗B, i.e., roughly the last quarter of the 15th to the last quarter of the 14th century BCE. Since neither tomb has been completely exposed, excavations in the protected area will continue in spring 2021.