bluuebunny/crossref_metadata_2025 huggingface dataset:
Tourism Management System Based on mobile Internet
Authors: Gui Xuefei
Published: April 2021

With the development of cloud computing, Internet of things, mobile communication, mobile Internet and other technologies, the development of intelligent, multi-dimensional and all-round tourism management information system has become the development trend of tourism informatization. This paper studies and realizes a mobile, information, intelligent and personalized intelligent travel service system for tourism industry by comprehensively utilizing the tracking and registration technology based on location and multi-sensor, tile map technology, 3D landscape map technology and virtual reality Superposition Technology of mobile augmented reality system. The system can provide a new perspective for tourists to understand the surrounding landscape and get a new interactive experience. The system includes three-dimensional landscape map, virtual roaming, route navigation, environment identification, historical building query, thermal map display, friend footprints, personal trajectory, Wechat sharing and other functional modules. Tourists can enjoy more convenient travel services at the same time. The model proposed in this paper has a certain reference value for the study of tourism management system.
Construction and Research of Digital Archives Cloud Platform Based on Big Data Management
Authors: Sun Yazhi
Published: April 2021

Cloud computing has the characteristics of super computing power, low cost and high security, as well as providing powerful data storage and network services. In the commercial field, it has begun to take shape. This paper attempts to introduce cloud computing technology into the construction of digital archives, analyzes the possibility and reality of the application of cloud computing technology services in the service and management of digital archives from the common point of view of cloud computing services and digital archives, and puts forward the corresponding ways of cloud computing application in digital archives. This paper analyzes and integrates all kinds of risks that digital archives may face under the cloud computing environment, and establishes the security evaluation index system including the security elements of information system and cloud computing technology. In this paper, fuzzy comprehensive evaluation method is used to evaluate the mathematical model of cloud digital archives security evaluation system, and a set of security evaluation system suitable for cloud digital archives is proposed.
Research on Image Rotation Recognition Based on Histogram Feature Description
Authors: Zhou Chunrong
Published: April 2021

Image recognition is a statistical pattern recognition problem in pattern recognition, which mainly includes four steps: image acquisition, preprocessing, feature extraction and selection, and pattern classification. In this paper, an omni-directional sequential feature description method based on F histogram is proposed. In this method, shapes are segmented by directional lines in all directions, the sequential feature description quantity between object segmentation segments in each direction line is calculated, the omni-directional sequential feature description quantity of shapes is constructed, and the similarity between shapes is calculated. In this method, the normal vector histogram is used as the point cloud feature descriptor, which can optimize the search of the corresponding point set, thus improving the ICP algorithm. By selecting the appropriate expansion center and expansion order, the recognition ability of the filter is improved. At the same time, using the concept of image moment, the characteristic moment vector of the target is constructed to identify the target with in-plane rotation and scale change. Based on the optimization strategy based on histogram feature description, the recognition speed of the algorithm is significantly improved.
Multilayer magnetic shielding for testing a superconducting single-flux-quantum circuit chip in liquid helium dewar
Authors: Wei L. , Wang G. , Li J. , Zhang S. , Hong G.
Published: April 2021

In order to reduce the influence of environmental magnetic field on the test of superconducting single-flux-quantum (SFQ) circuit chip in a liquid helium dewar, a multilayer magnetic shielding structure is designed to provide a clean magnetic field lower than 50 nT and achieve a shielding effectiveness higher than 60 dB. The magnetic shielding structure consists of three cylindrical layers with uniform 1 mm thickness. The first inner layer is made of NbTi which works as a strong diamagnet shell, while the outer two layers are made of permalloy which has high permeability at helium temperature. The superconducting quantum interference device (SQUID) was used to test the shielding performance of the structure under low frequency (0.1–100 Hz) magnetic interference at helium temperature. The results show that the radial and axial shielding effectiveness (SE) are about 80 dB and 68 dB, respectively, indicating that the multilayer structure has good shielding performance and can be used in the testing system of superconducting single-flux-quantum circuit chip.
Using a Tuned-Inerto-Viscous-Hysteretic-Damper (TIVhD) for vibration suppression in multi-storey building structures
Authors: Deastra P , Wagg D J , Sims N D
Published: April 2021

This paper explores the use of a novel tuned-inerto-viscous-hysteretic-damper (TIVhD) for reducing the seismic response of multi-storey building structures. The TIVhD is an inerter-based damper device consisting of a linear hysteretic damper connected in series with an inerto-viscous damper. The layout of TIVhD is similar to that of tuned-inerter-hysteretic-damper (TIhD) with an additional viscous damping element in parallel with an inerter. The design is motivated by the fact that most inerter designs cannot completely remove the parasitic damping due to friction, fluid compression, etc. Moreover, the use of linear hysteretic damping is considered to be a more realistic approach when material damping is present. In this paper, the TIVhD is installed between the ground and the first-storey and is tuned by firstly assumed the viscous damping coefficient to be zero. Then the other three parameters are optimised following the tuning procedure of the TIhD that is based on the fixed-point theory with additional fine-tuning procedure by targeting the first vibration mode of the multi-storey structure. The optimum TIVhD parameters are finally obtained using two scenarios: (1) amplifying its viscous damping coefficient and stiffness while keeping the inertance constant; (2) amplifying its inertance and stiffness while keeping the viscous damping constant. Both scenarios are aiming at the same reduction level of that given by the TIhD. Finally, the effectiveness of the TIVhD on reducing the structural response is demonstrated for both harmonic and seismic base excitation cases in the time domain. This has been made possible by a newly developed time domain response of linear hysteretic damping via the Hilbert transform and a time reversal technique.
Analytical fragility curve development of maternity and children’s M. Djamil Hospital building Padang due to earthquake and tsunami
Authors: Utami A C , Kurniawan R , Fauzan
Published: April 2021

M. Djamil Hospital is the largest public medical facility in Padang area with over 800 patient beds. The magnitude 7.6 Western Sumatra earthquake of September 30, 2009 caused the first floor of one housing outpatient services collapsed. Padang city is located in West Sumatra province which is recorded as an earthquake and tsunami prone area in Indonesia. Risk reduction strategy can be implemented by assessing the vulnerability of building through fragility curve. In this study, the fragility curve was carried out to an existing Maternity and Childrens’s M. Djamil Hospital building due to earthquake and tsunami in sequence. Building’s structural was modelled in ETABS v. 17 and analyzed by using Pushover analysis and Nonlinear Time History analysis. This structural model was subjected through a total of 40 ground motion data from El Centro, Northridge, Kobe and Padang. Each ground motion data was normalized from 0.2g to 2.0g of peak ground acceleration and continued with tsunami load. Analysis results consist of drift at yield point and structure maximum drift, which are then generated into a fragility curve based on Hazus standard. The result of earthquake fragility curve represents that the probability of slight damage level is 100%, moderate 100%, extensive 92% and collapse 5.4%. Meanwhile, earthquake-tsunami fragility curve represents the probability of slight damage level is 100%, moderate 100%, extensive 98% and collapse 11%.
The existence of multi-story buildings to reduce tsunami effects in the city of Padang, West Sumatra
Authors: Daoed D , Junaidi A , Sunaryo  , Hendra S , Irawan B B
Published: April 2021

The need for space for shelter as well as the place of business is always increasing in urban areas. To provide enough space, it is usually done vertically. The building becomes two or more stories high. This building grows along the highway and on the beach, for cities that are on the coast. Seawalls or dams are usually used to protect the driving force of the waves to shore and their construction is massive. But building prices are very expensive. However, the existence of multi-story buildings can also reduce and protect coastal areas against tsunami waves. However, not many researchers have examined this case by physically modeling it in the existing conditions. Based on that experiment research is conducted by imitating the real condition of the location of the affected waves. Simulations are carried out using models. The multi-story building model is made from styrofoam which is placed on the location map from satellite imagery. Then observed the effect of inundation and current propagation by generating waves. A single wave is generated by adjusting the height of the fall and the volume of water from the tank to the test object. The simulation results show a reduction in current propagation length and puddle depth of about 40%. The decrease in water depth is better as the floor of the building increases. As a recommendation, the multi-story building effect can help the community in determining the route and length of time for evacuation from the start of the incident to a safe place.
Optimum height of the retaining gravity wall
Authors: Bari F , Repadi J A , Ismail F A , riani  , Hakam A
Published: April 2021

Many failure cases of retaining walls caused by some factors, which are soil condition, planning design that did not meet the safety requirements, and the lack of knowledge or indecisiveness towards the selection of the retaining walls type for a specified height. In this research, the optimum height of a retaining wall of gravity wall type for sandy soil was planned. The research methodology was done by calculating external and internal stability from a stone gravity retaining wall. From the external stability analysis of 4 - 14 meters heights, it is known that the retaining wall still safe. The internal stability analysis obtained from 8 meters heights did not meet the safety requirements. Therefore, it is recommended from the research to use the height of 7 meters for the stone gravity retaining wall. The optimum height of retaining wall is planned in this research as the guidelines for engineers in planning the right retaining wall for the height as planned.
The analysis of correlation between Regime’s River coefficient and runoff coefficient (Case study in catchment areas of sidutan and reak)
Authors: Salehudin L , Wirahman W , Hasyim  , Rohani
Published: April 2021

The Sidutan and Reak Watersheds have 37.77 km2 and 23.66 km2 basin areas, both of which are still protected forests. Along with the increase in human activities, the community’s raw water needs in both watersheds can also influence the magnitude of the infiltration rate and runoff, where infiltration and runoff coefficient will affect the River Regime Coefficient (RRC). River Regime Coefficient is the magnitude of the ratio between the maximum and minimum daily discharge in a year in the river. Whereas to get runoff coefficient every year a single hydrograph and rain per hour are needed in a year. The relationship between river regime coefficients and runoff coefficients can produce a correlation equation is a linear equation. In the analysis, the runoff coefficient value in the following year in each river channel is enough to replace the value of the river regime coefficient with a linear equation. The analysis shows that the value of the River Regime Coefficient (RRC) with Runoff Coefficient in the Sidutan Watershed yields the equation Y = -2E-05x2 + 0.0048x -0.0539 with a coefficient of determination R2 = 0.6796. River Regime Coefficient (RRC) values obtained from 2011 to 2016 were 67.69; 43.99; 188.92; 53.78; 45.01 where the value is included in the low and too high classification range. The results of the analysis indicate the watershed is in bad condition. From the analysis of runoff coefficient (C) each watershed is 0.188; 0.101; 0.229; 0.163; 0.148, shows that the level of runoff coefficient (C) of the watershed is still in good condition. From the results of the analysis of the River Regime for the Reak River Basin, the equation Y = 0.0003x2 - 0.011x + 0.1618 with a coefficient of determination R2 = 0.7855. Where the RRC Value obtained in 2011 until 2016 respectively 27.46; 29.80; 31.06; 16.96; 14,11. The results of the analysis are included in the very low classification range and to a low degree. From the results of the analysis, the Reak River Basin is still in good condition.
Application of porous concrete to resolveflood on the roads
Authors: Utomo A B , Hidayatiningrum L F , Dhanardono B
Published: April 2021

In the rainy season, many cases of roads being submerged in water because of a lack of drainage capacity and low water absorption by the subgrade. This study utilizes porous pavement as an interlocking pavement to increase water absorption to the drainage layer and subgrade. Porous concrete is made from cement mixture : coarse aggregate = 1:6 with w/c ratio 0,4. The results showed the value of specific gravity, water absorption, compressive strength, and Na2SO4 resistance respectively 1.703 gr/cm3, 2.57%, 10.8 MPa, and 0.79%. To see the level of serviceability, no fine interlocking pavement is arranged above the drainage layer and the levelling layer, and then a trajectory and inundation test is performed. The result of inundation and track tests shows that the construction can pass water to subgrade without inundation and can withstand the wheel loader that is equivalent to 13000 kg so that it can be used for sidewalks, park lanes, and pavement with a maximum axle load of 8 tons.
A comparative study on bridge road works methods for flood tide management in Agats-Suator project
Authors: Dermawan H , Palamba W , Sebayang E
Published: April 2021

Currently, flood tide affects the accessibility of Agats-Suator Bridge Road. Therefore, local governments are making efforts to improve its infrastructure, one of which is in the bridge road construction previously used wood conventionally replaced with better concrete. This study examines the Agats-Suator Bridge Road Project, Asmat, Papua that compares the precast concrete system and conventional concrete system for flood tide management, in which workers were employed and materials were purchased from Surabaya. The purpose of this research is to calculate efficient scheduling conditions with a limited workforce on conventional and precast concrete implementation systems. The research method used in this research is a non-experimental quantitative method with comparative studies. Human resource allocation makes the workers scheduling more efficient by applying the principle of limited resource allocation. The research results show that the precast concrete system reach ideal conditions at rmax = 30 people with 18 weeks duration. Meanwhile, conventional concrete systems reaches ideal conditions at rmax = 89 people with 22 weeks duration. The result of resource allocation suggests that implementing a precast concrete system is more effective than implementing a conventional concrete system. The results of this study also function as a reference in selecting the concrete construction implementation systems for flood tide management in Agats-Suator Bridge Road Project.
Analysis of pedestrian crossing needs in the transmart shopping center area in Padang City
Authors: Irawan B B , Fitrahand D I S Rahmadani R A
Published: April 2021

Pedestrians are an important form of transportation in urban areas. The unavailability of pedestrian facilities will have an impact on the risk of traffic accidents and traffic delays. The Khatib Sulaiman road section in the city of Padang has land uses such as settlements, offices, hotels, trade and services. These conditions affect traffic conditions, especially for pedestrians. The purpose of this study is to calculate the potential number of pedestrians in the Transmart area and the selection of locations and types of pedestrian facilities. Pedestrian facility planning uses the Pedestrian Facility Technical Planning Guide (Pd 03-2017-B: 02 / SE / M / 2018: February 26, 2018). The pedestrian crossing survey results on the Khatib Sulaiman road on Saturday and Sunday (30-31 March 2019 at 14.00-18.00 WIB) obtained pedestrians who crossed an average of 278.25 people / hour. The recommended crossing facility is the People Crossing Bridge (JPO). The recommended pedestrian crossing bridge location is Point B with weight value 2.45 and coordinates 0° 54‘44”, 100° 21‘27”).
Traffic management at landslide disaster in West Sumatera and its impact to passenger and drivers
Authors: Purnawan  , Khairah M
Published: April 2021

West Sumatra is one of Indonesia province that always experiences landslides during the rainy season. Based on data from BNPB, in the last 10 years, 166 landslides have occurred in West Sumatra. The landslide materials covers partially and even the entire road wide, so it interferes the traffic flow activities in the lane. This study aims to identify traffic management that is carried out in the landslide disaster zone, the impacts arising from landslides are identified. The study was conducted by exploring the experiences of drivers and passengers when using vehicles in the West Sumatra. Structured questionnaires were created and distributed online and directly to respondents. From the results of data analysis, it was obtained that landslide most often occurred in the Padang-Solok road at Sitinjau Lauik region and in Padang-Padang Pariaman road at Silaiang region. These two routes have high traffic flow. Majority of landslide materials are soil, it causes traffic congestion. Traffic management by opening and closing oneway roads is a type that is mostly conducted to reduce traffic congestion, this activity is carried out by the police and the people around the location. The most impact that experienced by driver and passenger during waiting for cleaning the landslide material were tired and loss ot time.
An information management system for effective disaster relief operations
Authors: Patrisina R , Meilani D , Habib M
Published: April 2021

During an emergency situation, there is often confusion in information that can complicate disaster management efforts. For this reason, it is necessary to design an information system that can support emergency response operations. The purpose of designing this information system is to design a disaster management information system to strengthen emergency response operations quickly, precisely, and dynamically, and can be a decision supporter to facilitate emergency response operations. The system was developed using the waterfall method using the Object-Oriented Programming (OOP) approach. The design of information systems uses the PHP programming language and uses MySQL as a database. Then the system that has been designed is verified and validated using the Black Box method. The results of the information system design can provide dynamically needed information so that it can assist in scheduling and allocating volunteers, verifying data from donors, making TRC reports, collecting data and refugee needs, and estimating the distance between posts and evacuation sites
Potential environment and socio-economic impact of biofuel production in Malaysia: a preliminary review
Authors: Mohan D , Essam Yusuf , Katman H Y B , Ahmed A N , Shamsuddin A H
Published: April 2021

Malaysia is the second-biggest palm oil producer worldwide. Roughly 5.9 million hectares of area is planted with oil palm in Malaysia as recorded in 2019, making the palm oil industry one of the main income-generating industries for the country’s economy. As the palm oil industry in Malaysia grows, concern has been raised as several environmental and socio-economic issues are linked with the expansion of oil palm cultivation. The findings of this research contributes towards the preliminary investigation on the effect of biofuel demand in Malaysia on potential deforestation, greenhouse gas emissions due to land use changes and water pollution due to palm oil mill effluent (POME); and the effect of biofuel demand in Malaysia on other types of crops.
Study on robustness of rebound hammer and ultrasonic pulse velocity measurement in several concrete damage levels
Authors: Kencanawati N N , Akmaluddin  , Marlitasari R , Paedullah G
Published: April 2021

The results of reading the rebound number in a hammer test and velocity in an ultrasonic pulse velocity (UPV) test are usually associated with concrete compressive strength. A correlation or regression is provided to convert those parameters. However, several factors can influence this correlation. One of them is the level of concrete damage. The purpose of this study is to look at the robustness of hammer and UPV reading data in various concrete damage conditions. Experiments were carried out by testing three groups of concrete strength: 25, 35, and 45 MPa. All the concrete was tested using the UPV and rebound hammer test. The damage was determined as concrete which has decreased compressive strength by 30% (low), 50% (medium), and 80% (high) of the initial strength. The initial strength was the maximum compressive strength on each concrete group which was determined by compression testing. The rebound hammer data shows the correlation results that are almost the same as the correlation provided by the manufactures for concrete without damage and slight damage. But this is not the case with medium and highly damaged concrete, showing the results of the highly distorted correlation. The greater the level of damage, the greater the deviation. For concrete which damage level up to 80%, there is a deviation ratio of up to 3.6 times compared to the correlation value provided by the tool. Furthermore, the reading of UPV has a constant correlation without being affected by damaged concrete conditions up to the velocity of 3500 m/s. Thus, in a rapid assessment of the strength and safety of existing concrete structures, the robustness of a hammer test implements in concrete with sound and slight damage, but for concrete with beyond of elastic damage conditions, it must be accompanied by other tools such as UPV or sampling core.
Evaluation of mechanical and structural properties on the degradation of treated and untreated coir, jute and kenaf nettings
Authors: Anggraini V , Syamsir A , Mubin S M , Sofan A M H , Melasari J , Nasmirayanti R
Published: April 2021

Most of the soils in Malaysia are arid and infertile due to lack of buffering capacity and low clay activities that resulted in soil acidity. Moreover, high intensity rainfall and extreme conditions of slopes such as transient drought and lack of nutrients have reduced the survival and growth of potential plants. The use of vegetation and their relationship with microbes have great potential to alleviate soil acidity and erosion problems. The application of natural fibers in the construction industry was highly used as an additional or alternative source to be used in composites for increasing its strength properties. Natural fibers can innovative solutions to solve difficult problems, economically, enables the use of local materials means that natural fibers can be sustainable solutions. This paper consists of the technical results on the testing conducted to determine the strength of coir, jute and kenaf fibers. The objectives of this re-search are to manifest the effectiveness of new treatment on natural fibers netting to reduce degradability of the natural fiber netting to be used in acidic soils in Malaysia, to pick out the best chemical treatment for natural fibers to select the best natural fibers for rainfall area. The fibers have been treated by Sodium Hydroxide (NaOH) and Calcium Chloride (CaCl2). Six natural fiber nets have been provided with the size of each net is 500mm x 500mm (50cm x 50cm) and the spacing between the lines of the net is 17.5mm (1.75cm). Three nets are treated and the others are not treated. The nets have been placed on a slope at the site for 30 days and 60 days. The lab test that has been conducted is more focused on the strength properties of the coir, jute and kenaf fibers in terms of Tensile Strength. It has been found that treated fiber showed better performance than untreated fibers. The strength of fibers has been decreased respectively from 1st day on site to 60th day affected by climate changes.
Analysis of suspension bridge response due to earthquake under different soil conditions
Authors: Masrilayanti  , Jamil A , Rahmadona  , Annisa L , Kumalasari P
Published: April 2021

A suspension bridge is a long span bridge that has the advantage of the possibility of not having a pillar in the middle and using cables as the primary load bearer. Due to its long spans, the analysis of the bridge should be treated very carefully, especially under an earthquake. The earthquake that occurs will cause ground movement to affect the performance of the bridge structure. Furthermore, various soil conditions will also cause the existence of the bridge structure to experience differences. In this study, a super long-span suspension bridge is analyzed under different soil conditions. It is assumed that each support of the bridge is on the same ground condition and has a uniform ground movement. The bridge is then analyzed relating to the response of the bridge structure due to a uniform earthquake in the form of internal forces and displacement both in terms of static and dynamic analysis. Results show that soft soil induces a more massive internal forces response structure compared to hard soil.
Beyond the tsunami effect: Towards an understanding of the special autonomy budget policy in reducing poverty in Aceh
Authors: Yuliandri  , Kabullah M I , Fahmi K , Amsari F , Fajri M N
Published: April 2021

Aceh still struggling to reduce poverty after the tsunami disaster in 2004. Aceh was the 6 out of 34 provinces on the poverty problem in Indonesia in 2019. Although there area huge amount of special autonomy funds as asymmetric decentralization consequences, Aceh could not against poverty of the Acehnese people. This study attempt to explore the special autonomy budget policy by the Aceh government in the poverty reduction agenda after tsunami effect. The study used mixed legal study with a case study approach in the Aceh Provincial Government in 2019. The findings reveal that there are several factors of the low effectiveness of special autonomy funds in reducing poverty in Aceh, i.e. natural disasters, miss management of special autonomy funds, weak planning, absence of supervision, and inefficient local bureaucracy. In that sense, the Aceh government needs more policy reforms and institutional modernity to reduce poverty and promote opportunity for poor people.
Geospatial analysis for developing agriculture of marshlands to support regional food security in the era of pandemic Covid-19 in HST Regency, Kalimantan Selatan
Authors: Sutisna S , Sa’dianoor  , Maarif S , Bohari J A
Published: April 2021

Hulu Sungai Tengah (HST) Regency has a very large marshland in the South Kalimantan Province. Since 2019 HST is promoted to be a model for Indonesian local foods and agricultural development program, known as SERASI Program. SERASI stands for “Selamatkan Rawa dan Sejahterakan Petani” (or in English “save marshland and bring prosper to farmers”) that aimed to exploit marshland which was not productive yet. The SERASI will convert a non-productive caved swamp areas to a productive rice fields which able to support regional food security sustainably. In order to able define the suitable marshland area for SERASI Program in HST Regency precisely in the era of pandemic Covid-19, this research had been carried out by applying geospatial analyses method using Sentinel Satellite Imageries acquisitioned from two different epochs, i.e. of 20th February 2019 and of 20th February 2020. GPS coordinates collected from the field were used for ground truthing imagery data. The results of geospatial analysis have provided evident that paddy fields in caved marshland area is increased that means the SERASI Program is successful. From interviews’ data collected from 14 villages shows that the program of SERASI is accepted by local farmers and also local government. From image combination analysis concluded that the area of caved rice fields is suitable for developing agriculture in marshlands.
The role of communication as the disaster risk reduction in Indonesia capital city transference policy
Authors: Khumairoh Z , Widana IDK K , Sumantri S H
Published: April 2021

Disaster can not be avoided, but the risk of disasters is able to be diminished through mitigation. Mitigation in the form of discussion and communication becoming an instrument of society in facing the matters of life. This study describes the role of government in preventing to face the hazard potentials and disaster mitigations, such as natural hazards, disasters and conflicts through the effective communication. This study applied a descriptive qualitative approach through forum discussion group method and literature study. The informants in this study are the stakeholders of government organizations those are the experts of disasters, such as BNPB, BMKG, KLH and the academics. The theories in this study are the theory of communication and disaster mitigation focusing on the effective communication for enhancing the disaster risk reduction related to Indonesia capital city transference plans in Kalimantan. The result of this study shows that the role of disaster communication can help the government giving and socializing the information to the society in order to support the successful of disaster risk reductions.
The Impact of the COVID-19 Pandemic on Social Life Women Workers
Authors: Bangun E , Widana IDK K
Published: April 2021

COVID-19 gives a significant impact on female workers. Their rights that have been marginalized have been increasingly degraded during the PSBB (large-scale social restrictions). It becomes a double impact, socially or economically, because female workers as housewives are forced to bear the burden of families, and at the same time they have to be a mother to teach their children because of school-from-home programme. Some of them experience a more severe impact that the husband who loses his job, which means that the wife takes over the burden of the whole family. However, society (especially women) has social capital that is able to help them economically and psychologically in continuing their activities during pandemic. Using qualitative methods and social capital theory, we find that the existence of social gatherings of women can support their economy, or simply sharing with their friends has a direct impact on women’s mental health.
Preface of destructive m<5 earthquakes in Java island, 2015-2019
Authors: Julius Admiral Musa , Daryono  , Dewa Ketut Kerta Widana I
Published: April 2021

This study aims to denote the possible casualties and damages due to the M<5 earthquake. We used the desk study of literatures to explore earthquake disaster reports. The published significant and destructive earthquakes catalogue by BMKG Indonesia along 2015-2019 noted that six events out of them in Java island due to by below magnitude 5 (M<5) earthquakes. Those are sourced in the land and shallow depth focus on the active faults region. Those earthquakes also cause human losses, that is three events out of them induce casualties, and kill two (2) people. Preliminary analysis concludes that the short distance to earthquake source and local site condition was responsible for this unexpected building damages. We suggest this events to be the lesson learned for disaster risk managers to consider the low magnitude earthquake also able to generate the high hazard on the certain seismic prone areas.
Shear wave velocity as a tool for characterising undrained shear strength of Nordic clays
Authors: Long Mike , D’Ignazio Marco
Published: April 2021

There has been increasing recent use of shear wave velocity (Vs) measurements in geotechnical engineering practice. This has been driven by advances in cost effective and efficient methods of determination of Vs. Traditionally Vs measurements were used for seismic hazard assessment or dynamic analyses. However, they are being increasingly used for general site characterization studies, determination of strength and compressibility parameters by empirical correlation, assessment of sample disturbance effects and in the quality control of ground improvement schemes. This paper will briefly present the methods used to determine Vs and give some examples of Vs measurements in clays from Finland, Norway and Sweden. Despite similar depositional environments the range of Vs profiles for these three countries is significantly different. Differences in the profiles appear to be consistent with differences in basic clay properties, e.g. water content, density or plasticity. Nevertheless, the relationship between Vs and undrained shear strength (su) of clays appears to follow a similar trend for clays from Sweden, Finland and Norway. Correlations between Vs and su exist in the literature for Norwegian clays based on DSS tests. This paper studies the relationship between Vs and su from field vane test, which is commonly used in Finnish geotechnical practice. The proposed correlation is based on data from Sweden and Finland and is meant to be used for preliminary estimate of su from Vs in absence of test data or for validation of available test data.
Characterization in one-dimensional compression of a Danish Paleogene Clay
Authors: Di Remigio G , Rocchi I , Zania V
Published: April 2021

The North Sea Basin is characterized by the presence of highly plastic, stiff Paleogene clays sedimented between 65.5 and 43 millions of years ago. During the Quaternary Period, this area underwent a series of cyclic glaciations that overconsolidated the underneath clay deposits and sheared the shallower layers. Different studies focusing on these superficial, folded strata are present in literature. On the other hand, less information are available regarding the mechanical behaviour of the deeper, intact layers. However, a good knowledge of these layers mechanical properties is necessary to guarantee an efficient design of the infrastructures built on these formations. This work focusses on the characterization of the Paleogene Røsnæs Clay Formation present in the Fehmarn Belt area, between southern Denmark and northern Germany, where a submerged tunnel will be constructed. The mechanical properties of the Intact Røsnæs Clay layer were determined and compared with those of the Folded Røsnæs Clay. Incremental Load Oedometer tests were performed by applying different load cycles in order to stress the sample below, in correspondence and above the estimated preconsolidation stress. The results were compared with those obtained from testing reconstituted samples in order to assess the influence of structure. This was done quantitatively by analysing the stiffness, the compressibility, and swelling indices. Environmental Scanning Electron Microscope micrographs were used to detect the presence of micro-folding. The mineralogical consistency among the different Oedometer tests was evaluated by means of X-Ray Diffraction. Despite the homogeneity in the mineralogy, differences in both the microstructure and the 1D behaviour of the Folded and Intact layers were observed. In particular, the Folded layers appear to have greater compressibility and swelling potential. These differences should be taken into consideration when building on partially pre-sheared Paleogene formations.
Random sampling of geosynthetics in Finland
Authors: Leppänen M M , Kalliainen A , Uotinen V-M
Published: April 2021

NorGeoSpec is a Nordic system for certification and specification of geosynthetics and geosynthetic related products. Traffic authorities of the member states have composed the guidelines and agreed on a 5-class specification system for geotextiles used for filtration and separation. Recently the quality certification system has been extended to include the reinforcement function, too. The classification system has made the specification of geotextiles easy for the designer, thus increasing the use.

The NorGeoSpec process includes a third-party quality control and audits, i.e. an inspection of the production process and testing of the products in an independent testing laboratory, in addition to the producers’ continuous quality testing. Also, continuous surveillance including unannounced random product sampling and control checks is possible.

With the support of NorGeoSpec, Finnish Transport Infrastructure Agency has carried out a random products sampling on geotextiles and reinforcing geosynthetics in 2015-2018. In addition, random sampling was made on roadside groundwater protection projects using geosynthetic clay liners and geomembranes.

The random sampling project has increased the knowledge of geosynthetics. The results of random sampling have shown some deviations from requirements and the variation between laboratories. Based on the results, the requirements on sampling and testing prior the use at the project site to prove the compliance has been added to Finnish general quality requirements (InfraRYL).
Testing sensitive clays through time and length scales
Authors: Birmpilis Georgios , Dijkstra Jelke
Published: April 2021

In the Nordics, engineering of sensitive soils is of vital importance for realising the urban environment and the infrastructure connecting and underpinning it. The hydro-mechanical behaviour of sensitive clays is strongly affected by the geological deposition history in the area and subsequent human activities resulting in changes in stress and environmental loading. Finally, the characteristic physico-chemical identity of the clay-water system is expressed by the sensitivity of the material. A combination of classic geotechnical tests in the laboratory needs to be complemented with state-of-the-art technologies for material analyses, in order to deepen our understanding of the interaction between the colloidal nature of the clay and the observed response at the engineering scale. Until now these activities have been performed separately. The microstructural observations using various microscopy techniques were not directly combined with classic geotechnical tests. In contrast, the work presented herein showcases methodologies for simultaneous monitoring of fabric and mechanical probing under controlled conditions on samples of sensitive clay. In order to enable real-time fabric measurements of samples of sensitive clay two non-invasive techniques are utilised: X-ray Scattering (XS) and X-ray Computed Tomography (XCT). Furthermore, a bespoke apparatus for sample probing is designed and built at Chalmers University of Technology. The design of the apparatus is adapted to the special challenges of very soft samples and addresses issues of sample quality in soft soil testing (i.e., sample mounting, membraneless configuration). The intention of this work is to demonstrate the feasibility of expanding geotechnical testing outside the limits of the traditional geotechnical laboratory, combining geotechnics with state-of-the-art technologies for material analysis. This, in the end, provides a critical view on the perception of the material and its constituents that aims to contribute in improvement in geotechnical laboratory testing and the development of advanced constitutive models for sensitive clays.
Effect of Strength Anisotropy on the Stability of Natural Slopes
Authors: Aamodt Magnus T , Grimstad Gustav , Nordal Steinar
Published: April 2021

It is well known that low plasticity soft clays have large variations in undrained shear strength with the direction of loading. Laboratory experiments show typically a cross anisotropic behavior, where the undrained shear strength in compression is significantly larger than the undrained shear strength in extension. The total stress based NGI-ADP model, as available in PLAXIS, captures such shear strength anisotropy well, when applied to embankments on or excavations from a horizontal or almost horizontal terrain. However, for non-horizontal terrain the direction of the in-situ principal stresses are inclined, and the axis of anisotropy are hence expected to be somewhat inclined too. As for natural slopes, the effect on the calculated factor of safety due to this inclination is not yet well documented. Previous studies show that this effect might not be a negligible effect and can increase the factor of safety by about 10% for gentle natural slopes. In order to study this, a new ADP model has been implemented in PLAXIS. The formulation is inspired by results from DSS laboratory testing where samples were consolidated under inclined effective stresses before shearing in the same or the opposite direction of the initial shear stress. As expected, the model shows higher factors of safety when applied to a slope than a conventional analysis. The paper then discusses to what extent this represents a real safety margin that has previously been neglected.
Investigations on load-bearing behavior of soil nailing combined with flexible facing for slope stabilization
Authors: Lehn J , Biczók E , Roduner A
Published: April 2021

Soil nailing combined with a flexible facing made from steel wire meshes is a commonly used and economically efficient structural system for slope stabilization. Soil nails reinforce the natural soil, which strongly decreases earthwork compared to other retaining and supporting systems. The steel wire mesh ensures the transmission of force and guarantees the safety against local and global slope failure. In a first step the paper describes the structural system of soil nailing combined with flexible facing. For instabilities near the surface (local instabilities) state of the art calculations are outlined. To verify and improve the existing designing approaches, full scale in situ tests were conducted. Among others, different flexible facing systems, nail arrangements, and soil conditions were investigated. The flexible slope stabilization system and the soil were installed in a large box with a dimension of 12 m x 10 m. After the installation, the test box was lifted up stepwise using a crane. Different parameters like three dimensional deformation, rope forces, as well as the moment and normal forces in the nails were measured. The test results are used for numerical back analysis with a three dimensional finite element method. Using the validated and calibrated numerical model, extended parametric studies by 2-dimensional and 3-dimensional non-linear finite element analyses will be conducted in the future to identify the main influencing parameters.
Emission reduction through preconstruction and utilization of alternative materials in infrastructure projects
Authors: Pahkakangas S , Dettenborn T , Forsman J , Niemelin T , Rantala K , Suominen M
Published: April 2021

Construction have a significant impact on the amount of emitted green-house gas (GHG) and a potential to cut emissions is quite substantial. In this article, possibilities provided by preconstruction activities and utilization of alternative materials are discussed. Preconstruction means actions to be taken in advance when soils in the construction area are too soft. These actions may be e.g. deep mixing, replacement or preloading. Considering that constructed subgrades, ground improvement and some other earth works required for the infrastructure project can be very energy-intensive, emissions can be reduced substantially only if preconstruction options, areal mass balance and potentiality of alternative materials are identified early enough. Examined case studies also focus on possibilities to reduce emissions related to certain materials e.g. deep mixing binding agents. In deep mixing, blend of cement and quick lime is the most traditional binder component. Therefore, reducing the amount of cement + lime and selecting the cement type have a great impact on CO2 emissions. Cement amount can be reduced by alternative materials such as fly ash, blast furnace slag or gypsum. Possibilities to reduce CO2 emissions were studied in various infrastructure projects and reflected to climate strategies. The studies were focused on areas and operations where changes were possible such as transportation, construction materials or subgrade construction methods. This article describes the case studies related to construction of various infrastructure projects and identified possibilities to reduce emissions.
Tension tests on bored instrumented piles installed in marine Eocene clay
Authors: Knudsen J , Sorensen K K , Steenfelt J S , Trankjær H
Published: April 2021

This paper presents parts of the results from two full-scale loading tests (tension) on bored cast-in-place piles installed in high plasticity marine Eocene clay at a test site in Hinge, central Jutland, Denmark. Testing was carried out to investigate the development and distribution of shaft resistance on the test piles. Each test pile was instrumented with distributed fiber-optic strain and temperature cables, in addition to traditional vibrating wire strain gauges and tell tales. Selected examples of retrieved data are presented. The measured shaft resistance is compared to an analytical method based on the Danish National Annex to Eurocode 7, part 1 which represents a conservative estimate for the shaft resistance of bored piles. The results from the two full-scale loading tests (tension) on bored cast-in-place piles in marine Eocene clay show that the Danish code-requirement, concerning shaft resistance, is too conservative.
Use of a 3D stratigraphic model as tool for improved communication and risk assessment in large infrastructure projects
Authors: Kahlström M , Mortensen P-A , Hauser C , Hansen Børner N
Published: April 2021

As more work processes are moving into the digital space, such as collaborative BIM environments, the toolbox of the geotechnical engineer needs an update to efficiently keep track. Visualization of soil conditions in 3D space, using implicit modelling tools, is rapidly changing how geotechnical engineers engage with digital data. For a large railroad development in Norway, a 3D stratigraphic model is developed to act as a hub for soil interpretation, decision making and communication of geotechnical challenges and risks. Lithology is interpreted from all geotechnical boreholes and used as basis for the model together with a terrain model from GIS. The model is dynamically updated as new geotechnical soil investigations are performed and is actively used in the geotechnical design work. Overall, the 3D stratigraphic model is successfully applied for: (1) Visualization of geotechnical uncertainty with a classification based on radial distance to the borehole, (2) communication of sub-surface conditions and risk to project stakeholders and (3) efficiently exporting cross-sections as basis for geotechnical analysis.