Soft Deposits Research Articles

Railway embankment failure trends and monitoring – lessons learned from the Anglia route

UK railways were constructed with little consideration of engineering practice and with climate change and the associated greater frequency of extreme weather events, comes the impact on earthworks stability and risk to public safety. Many embankments on Network Rail’s Anglia route have shown a gradual degradation through their steep upper slopes and progressive failure within predominantly clay embankment material and underlying soft deposits. A regional wholistic view allows identification of common geotechnical trends and risk categorisation to better enable prioritisation of asset management. Understanding when to intervene is crucial and monitoring the behaviour of earthworks is a vital asset management tool to control risk and extend lifespan. To be a wise investment, slope instrumentation must be properly thought out in line with a detailed interrogation of the site and alongside a well-developed conceptual model. Automated monitoring can bring greater control and allow more accurate evaluation of intervention but must be assessed in line with prioritising large areas with limited budgets. Correct targeting of ground investigation and ensuring sufficient and reliable data can optimise mitigation and provide confidence the solution has provided resilience to railway infrastructure.

Simplified site response analysis for regional seismic risk assessments

Seismic risk assessment on a regional scale requires an estimation of ground motion intensity and its spatial variation over large geographical areas. This task is particularly challenging in the presence of very soft soil deposits where significant amplification occurs at specific frequencies that are often referred to as local resonances. It is often not feasible to conduct a nonlinear site response analysis at thousands of sites of interest across a region such as an urban area due to the computational effort involved and the required detailed information on soil profiles at each site. Thus, in regional seismic risk analyses the hazard is typically represented by a field of response spectral ordinates estimated by ground motion models. This study proposes a simplified site response analysis procedure to improve the characterization of spectral ordinates to be used in regional seismic risk assessments. In the proposed procedure, reduced-order models are used to conduct site response analysis using very few parameters to transform response spectra at rock outcrop into response spectra at the surface of each of the sites. A particular emphasis is given to soft-soil sites characterized by low shear-wave velocities overlaid on rock or firm soils. A non-uniform continuous shear beam model with a parabolic variation of shear modulus along the depth and modal damping is used in combination with Random Vibration Theory. It is shown that the proposed approach provides better estimates than those of ground motion models or physics-based ground motion simulation models which often cannot capture the local resonances. Site-specific validation of the shear beam model and overall simplified site response analysis is performed at four soft-soil sites in San Francisco, California. Despite its simplicity, it is shown that the proposed procedure adequately captures the amplitudes and spectral shapes of the motions. It is also shown that in conjunction with ground motion models or physics-based models, the proposed simplified site response analysis procedure can be used to efficiently simulate the seismic hazard on a regional scale through an example of a regional seismic hazard analysis of 160 softer soil sites in Downtown San Francisco during the Loma Prieta earthquake.

Numerical analysis of a deep and oversized group excavation: A case study

Group excavations are composed of several individual excavations adjacent to each other with simultaneous or successive construction sequences (CS), which are distinctive from individual excavation in terms of the performance of excavation. In this study, a hyper-scale 3D finite element model was established to investigate the deformation behavior of a diaphragm wall system retaining a deep and oversized group excavation (DOGE) in Shanghai soft clay deposits. The numerical model simulated the practical construction stages and sequences, and it was verified by a series of comparisons with field measurements. Based on the numerical model, the spatial effect of the performance of DOGE in the process of excavation stages was investigated in this study, which cannot be addressed by limited field measurements. Furthermore, the effects of partition walls and CS on the deformation control were discussed to provide practical suggestions for oversized and deep excavations. The results indicate that the employment of bi-partition walls to divide the oversized excavation into several small pits and mono-partition walls and cross walls to further divide the pits near the metro lines into smaller ones, was proved to have significant effectiveness in controlling the wall deflection and protecting the adjacent metro line. For the partition wall, the magnitude and direction of the wall deflection primarily depended on the initial excavation, while the influence of subsequent excavation activities proved insignificant. Thus, it should be noted that the effect of the initial excavation should be especially concentrated. The findings can help optimize similar DOGE engineering.

Ground Surface Effect of Earth Pressure Balance Tunnelling in Deltaic Deposits: A Case Study of Line 9 of the Barcelona Metro

The 47.8 km long Line 9 of the Barcelona Metro is one of Europe’s longest urban metro lines. Its southern section connects the city to the airport, being entirely excavated through soft deltaic deposits, promoting more sustainable mobility by reducing significant road traffic. This study identifies the most accurate method for predicting surface settlements caused by tunnel excavation using ground movement monitoring data. Several methodologies were assessed, with the Mean Absolute Error (MAE) and Mean Relative Error (MRE) calculated to evaluate their performances. The methods considered were Peck’s Gaussian curve method, Sagaseta’s method, and Verruijt and Booker’s method, with MAE values of 0.66 mm, 0.50 mm, and 0.48 mm and MRE values of 49%, 45%, and 36%, respectively. Verruijt and Booker’s method proved the most effective for predicting settlement, minimising surface impacts, improving building sustainability, and reducing environmental contamination from chemical injections. A sensitivity analysis was also conducted by comparing the monitoring data from Line 9 with data from 45 other tunnels excavated worldwide in deltaic soils. This analysis aimed to develop rapid predictive models applicable to different locations. The methodologies proposed for estimating ground settlements relied on specific parameters, particularly the K value, which was consistent across all deltaic soil locations, with values ranging from 0.45 to 0.55.

Malignant Soft Tissue Deposits in Advanced Cancer Larynx, a Prospective Study.

The purpose of this study was to evaluate the incidence and predictors of malignant soft tissue deposits (MSTDs) in advanced laryngeal carcinoma. MSTDs prognostic value on locoregional recurrence within 2 years after curative surgery was also studied. 40 patients with cT3/cT4 N0 laryngeal squamous cell carcinoma (SCC) were prospectively involved in the study. Soft tissue specimens were histopathologically examined for MSTDs. MSTDs were observed in 4 patients. Six patients had extranodal extension (ENE), four of whom showed MSTDs. All patients with MSTDs had associated comorbidities. cTNM staging, preoperative tracheostomy, tumor grade and surgical margins were not related to the incidence of MSTDs. The incidence of MSTDs in our report was less than that previously reported in the literature. MSTDs did not influence locoregional recurrence and did not influence the overall outcome. MSTDs were less significant as a prognostic factor in comparison to other factors such as ENE.

Numerical modeling of site response at large strains with simplified nonlinear models: Application to Lotung seismic array

Abstract Site response analyses at large strains are routinely carried out neglecting the shear strength of soil and the stiffness degradation due to the increase in pore pressures, leading to unrealistic predictions of the seismic response of soil deposits. The study investigates the performance of a simplified nonlinear (NL) approach, implemented in the Deepsoil code, constituted by coupling a hyperbolic model incorporating shear strength with a strain-based semi-empirical pore pressure generation model. The first part of the study, based on a large one-dimensional parametric study, shows that above a shear strain of 0.1%, it is necessary to include shear strength in the site response modelling to get more realistic results. Then, the approach has been evaluated with reference to the well-known downhole Large-Scale Seismic Test array located in Lotung (Taiwan): numerical results have been compared with recordings in terms of acceleration response spectra and pore water pressure time histories at different depths along the soil profiles. The comparison shows that the NL simplified model is characterized by an accuracy comparable with more sophisticated advanced elasto-plastic NL analyses adopting essentially the same input data of the traditional equivalent linear approaches(shear modulus and damping curves) and simple physical-mechanical properties routinely determined during geotechnical surveys (i.e., shear strength, relative density, fine content). This approach is therefore recommended for site response analyses reaching large strains (i.e., soft soil deposits and moderate-to-high input motions).

Observed Behaviors of an Ultra-Deep Excavation with an Innovative Pre-Support System in Shanghai Soft Deposits

Observed Behaviors of an Ultra-Deep Excavation with an Innovative Pre-Support System in Shanghai Soft Deposits

An Insight into Supportive Periodontal Therapy and Maintenance Care

Abstract: Periodontitis is a painless destructive disease of the tooth supporting structures that progresses silently, hence it’s a big challenge for clinicians to motivate the patients for therapy. Several factors influence the treatment outcome such as genetic variations, smoking, systemic complications, stress, trauma from occlusion, iatrogenic dentistry, etc. There is ever-growing evidence that recall visits are prerequisites for the success of therapy. At the personal level, maintenance is difficult for an average patient as this demands frequent elimination of soft and hard deposits from all the possible surfaces, hence highlighting the significance of repeated professional care at regular intervals. An effective outcome of the therapy can be achieved by a fruitful combination of both active and supportive periodontal therapy, hence reducing the possibility of re-infection and arresting the disease progression. Keywords: Supportive Periodontal therapy; an extended trimeric model; compliance; risk assessment.

Experiment and analysis on dynamic characteristics of marine soft clay

A series of cyclic triaxial tests were conducted on marine soft clay deposits to establish and validate a predictive model for cumulative plastic strain. Additionally, a numerical model of particle flow code in cyclic triaxial tests was developed. The effects of confining pressure, moisture content, and dynamic stress ratio on the dynamic properties of marine soft clay were examined, considering factors such as volume deformation and microscopic failure patterns. The results indicated that both the predictive model and numerical model showed strong consistency with the experimental data. The plastic strain of marine soft clay was influenced by moisture content, stress ratio, and confining pressure in a consistent manner, with moisture content being the primary factor. A predictive model for the cumulative plastic strain of marine soft clay was successfully established, allowing for the evaluation of dynamic properties from the perspective of cumulative plastic strain. During the loading process in the numerical model, microcracks within the soil structure gradually compacted, and the main displacement of the specimen extended from the vertical center axis to the sides, ultimately resulting in shear damage.

EFEKTIVITAS BERKUMUR LARUTAN DAUN BINAHONG TERHADAP INDEKS PLAK PADA SISWA KELAS III – IV ANAK SEKOLAH DASAR NEGERI 21 MANADO KOTA MANADO

Dental plaque is a soft deposit that adheres tightly to the surface of the teeth, consisting of icroorganisms that multiply in an intercellular matrix if a person neglects dental and oral hygiene. Anredera cordifolia (Ten) Steenis or commonly known as binahong or gondola is a creeping plant that is perennial (long-lived). The benefits of the binahong leaf plant are enormous in the world of medicine, empirically binahong can cure various types of diseases. In medicine, the part of the plant used can come from the leaves. Research using boiled leaves has found many ingredients, which were stated by (Setiaji, 2009) that flavonoids have various effects, namely analgesic, anti-inflammatory and as a vasolidator. The aim of this research was to determine the effectiveness of gargling binahong leaf solution on plaque index. This type of research is True Experiment research with a "one group pre-post test" design, conducted in June located at SD Negeri 21 Manado, Manado City. The total population of class III and IV students was 50 respondents with a total research sample population based on the inclusion criteria of 34 respondents. The instruments that will be used in this research are dental examination tools in the form of diagnostic sets, disclosing agents, personal protective equipment, plaque examination formats, mouthwash cups and precision digital scales. The data obtained was tabulated and analyzed using paired sample t-test. Based on the results of the Paired sample t test showing that there is a significant difference seen from the value of P = 0.000 (P<0.005), it can be concluded that H1: rinsing the mouth with binahong leaf solution is effective on the accepted plaque index.

THE EFFICACY OF COCOA BEAN EXTRACT MOUTHWASH CONCENTRATION IN REDUCING PLAQUE INDEX IN THE ORAL CAVITY AMONG PRIMARY SCHOOL STUDENTS AT SDN KAYEE LEU, INGIN JAYA SUBDISTRICT, ACEH BESAR

Oral and dental diseases have a high prevalence in Indonesia, with 88.8% of the population experiencing dental caries and periodontitis. Dental plaque is a soft deposit that tightly adheres to tooth surfaces and is composed of microorganisms that contribute to the development of dental caries. Preventing caries and controlling plaque can be achieved through the use of mouthwash, which is more effective when herbal mouthwash containing antioxidants and antibacterial agents is used. Cocoa bean extract (Theobroma Cacao L.) contains secondary metabolites such as alkaloids, flavonoids, tannins, steroids, and exhibits antibacterial and anti-inflammatory properties, as well as strong inhibitory effects against S. mutans bacteria. The objective of this study is to determine the effectiveness of cocoa bean extract mouthwash concentration in reducing the plaque index in the oral cavity. The research methods included laboratory experiments and quasi-experiments with a post-test only control group design. The research was conducted at the Faculty of Veterinary Medicine laboratory, University of Syiah Kuala, and SDN Kayee Leu, Aceh Besar, involving 30 students. Data analysis was performed using ANOVA in the SPSS program. The results of the study indicate that the phytochemical analysis of cocoa bean extract contains alkaloids, steroids, terpenoids, saponins, flavonoids, phenols, and tannins. The Minimum Inhibitory Concentration (MIC) of cocoa bean extract mouthwash on the growth of Streptococcus mutans was observed at a concentration of 1%, and no Minimum Bactericidal Concentration (MBC) was found in this study. The 1% and 2% concentrations of the mouthwash effectively removed plaque compared to the 0% concentration. In conclusion, the use of cocoa bean extract mouthwash is effective in reducing the plaque index. Further research should consider clinical trials to explore its potential as an herbal remedy.

Comparative Study of One-Dimensional Site Response Analysis on Deep Soft Clay Deposit using DEEPSOIL and NERA

Numerous high-rise buildings have been built in major cities in Indonesia. In high seismicity areas, such as Surabaya, the seismic behavior of structures is notably affected by the seismic characteristics of the subsurface soils. Typically, site-specific response analysis (SSRA) is conducted to determine the peak ground acceleration experienced at the ground surface. This paper compares one-dimensional site response analysis on deep soft clay deposits in Surabaya city using two commonly used 1D site response programs: DEEPSOIL and NERA (Non-linear Earthquake Site Response Analyse). A soil column model with 24 m thick very soft clay was developed. To represent different ground motion intensity, three levels of input motion were applied at the bedrock with peak ground accelerations (PGA) of 0.07g, 0.3g, and 0.51g. These input motions were then applied in a one-dimensional non-linear site response analysis to evaluate the seismic soil response at the surface. The evaluation involves examining the peak ground acceleration (PGA) and maximum shear strain profiles obtained from both software programs. The results indicate that the non-linear analysis conducted with NERA yielded greater amplification factors across all periods compared to the results obtained from DEEPSOIL. For the low-intensity motion, both software showed amplification of the input motion for all periods. In contrast, the spectral response obtained with DEEPSOIL demonstrated de-amplification trends for periods less than 1 s for the case of medium and high-intensity motions, whereas no de-amplification was observed from the results of NERA. This difference results in the amplification for medium and high-intensity motions can be attributed to the strength correction factors that are implemented in the DEEPSOIL software to take into account the representative shear strength of the soil layers.

STATUS DEBRIS INDEX SEBELUM DAN SESUDAH DILAKUKAN DEMONSTRASI MENYIKAT GIGI DENGAN CARA ROLL TECHNIC PADA SISWA KELAS IV & V SEKOLAH DASAR KARTIKA XXI-5 MANADO

Demonstration of how to brush teeth is a teaching method by presenting lessons through direct demonstration of the object or showing a process or procedure. Roll Technique is the method most often recommended because it is simple but efficient and can be used throughout the mouth. Debris Index (DI) is a score (value) of soft deposits that occur due to food residue attached to the tooth surface. This study aims to determine the status of the debris index before and after a demonstration of brushing teeth using the roll technique. The type of research is experimental research with a One Group Pretest-Posttest design. The total population was 52 students and the total sample was 48 students, the time of the research was in May 2019 at Kartika XXI-5 Manado Elementary School. This research was to see the difference in debris index status before and after the demonstration method of brushing teeth using the roll technique using a paired sample t test. The results of this study showed that the average debris index before the demonstration of brushing teeth using the roll technique for 48 respondents was 2.31, while the average debris index after the demonstration of brushing teeth using the roll technique for 48 respondents was 1.48. The calculated t value is 10.335 with a sig of 0.000. because sig <0.05, it can be concluded that Ho is rejected and H1 is accepted, which means there is a difference in the status of the debris index before and after a demonstration of brushing teeth using the roll technique for students in class IV & V at Kartika XXI-5 Elementary School, Manado.

Impact of Cocoa Seed Extract Toothpaste on Plaque Reduction in Pediatric Populations

Plaque is a soft deposit that forms a helical biofilm layer and attached tightly to the tooth surface, in which its presence requiring the use of specific control agents. The safest and most effective plaque control is to use a toothbrush and toothpaste. On the other hand, extract from Theobroma cacao L. seeds contains antioxidant and antibacterial secondary metabolites which could act as a toothpaste active agent. The aim of this research was to determine the impact of Theobroma cacao L. seeds-added toothpaste in reducing plaque index of among children. This is a non-blinding clinical experiment with a pre-test and post-test research design. The research subjects were 30 healthy children aged 8-10 years which were randomly divided into three arms (treatment and control). The results revealed that Theobroma cacao L. extract used as the active ingredient contained contains phenolics, tannins, flavonoids, terpenoids, saponins, and alkaloids. Significantly higher plaque index reductions were observed among children treated with toothpaste containing 1% (mean difference=2.060; p=0.06) as compared to control. In conclusion, the Theobroma cacao L. seeds-added toothpaste could significantly reduce plaque index among healthy children.

Determination of the geophysical signature of soft-clay and hard lateritic soils and the implications on geotechnical works using electrical resistivity imaging

Understanding the geophysical signature of subsurface is quite essential in mapping site conditions for geotechnical engineering and simulating geophysical surveys, especially in coastal areas. This article presents a comparative geophysical study of topsoil (often refer as engineering layer) of soft clay deposit and hard lateritic soil to evaluate the implications on geotechnical work using electrical resistivity imaging (ERI). The results of the 2D ERI show that the hard lateritic soil produces three distinctive geological layers with the topsoil having high apparent electrical resistivity (AER) values varying between 300 Ωm–1000 Ωm and a thickness between 2.0 m – 10.0 m. The layer between the unsaturated and saturated regions has a moderate layer AER and thickness values ranging from 100 Ωm–300 Ωm and 2.5 m–9.5 m, respectively. In contrast, the saturated (weathered) layer has a low AER value (< 100Ω m), which represents the regional groundwater unit, located beneath the subsurface of a depth > 6.0 m. However, the soft clay soil shows no distinctive subsurface layers, as it is characterized by a nearly homogeneity subsurface of poor AER variability. The top-soft clay deposit has very AER values ranging from 11.0 Ωm–80 Ωm, which extends beyond 6.5 m. Higher and lower AER values noted within the overburdened topsoil of lateritic and clay extractions, respectively, were due to the accumulations of compacted clay and lateritic soil, which are very essential for geotechnical works. In addition, the geophysical signal was conspicuously attenuated in soft clay soil, which shows that soft clay soil is not a favourite target of geophysical investigation. However, the geophysical signals in hard lateritic generate a fine geo-electrical layer pattern. It was also noted that the existence of soft clay and lateritic soil decreases with depth. This kind of information is very essential in geotechnical works.

Adaptability of VisCalor versus bulk-fill composites using scanning electron microscope: an in-vitro study

Purpose To evaluate the marginal integrity of two types of bulk-fill composite resins in Class I box-shaped cavities. Materials and methods Forty extracted human sound molars were selected. The teeth were fixed with sticky wax to the base of plastic cylinder and the cylinder was filled with self-curing acrylic resin so that only root was embedded. Simple Class I box-shaped cavities were prepared using a fissure carbide bur with water spray and finished with fine-grained flame burs. The overall dimensions and depth of the cavities were standardized as follows: 4 mm length mesiodistally and 3 mm width buccolingually and up to 4 mm depth. All prepared cavities were bonded using Futurabond M+ one-step self-etch adhesive system. The teeth were randomly divided into two groups (n = 20 teeth each): group I: specimens were restored with VisCalor composite bulk-fill composite resin, which is heated before insertion using a VisCalor dispenser dental device. Group II: specimens were directly restored with X-tra fill bulk-fill composite resin without preheating. After curing, finishing and polishing were performed. Each group was subdivided into two subgroups a and b (n = 10) according to whether subjecting 500 thermocycling fluctuations or not. Each specimen was sectioned buccolingually through the center of the composite resin restoration in two halves, and then cleaned under running tap water and subjected to thorough ultrasonic cleaning to get rid of both soft and hard surface deposits. All sectional samples were fixated in cylindrical carriers, and a thin layer of gold was applied to the surfaces. The marginal adaptation of composite restorations and ultramorphology of adhesive bonds were analyzed at ×50, ×1000 magnification, with a scanning electron microscope. ×50 magnification was utilized to measure the length of margins free gap in enamel and dentin by Autodesk Auto CAD program and expressed in mm/percent. All data of measurements of the length of nongaped margins in enamel and dentin are collected, tabulated, and statistically analyzed. Results Group Ia (VisCalor bulk-fill not thermocycled), recorded the highest mean value of marginal free-gap with 10.26 ± 0.27 mm (93.31%), while group IIb (X-tra-fill bulk-fill thermocycled) recorded the lowest mean value in 7.90 ± 0.26 mm (73.04%) and the difference was statistically highly significant (P = 0.000). In general, group I recorded higher mean values of marginal free gap and adaptation in mm/percent than group II, and the difference was statistically highly significant at P value of 0.000 (9.86 ± 0.55 and 8.23 ± 0.39 mm and 89.15 ± 5.38 and 74.89 ± 3.69%, respectively). Bulk-fill restorations without thermocycling exhibited a higher mean value of marginal free gap and adaptation in mm/percent than the thermocycled one with a significant difference recorded at P value of 0.005. Conclusion Using preheated VisCalor bulk-fill composites could decrease the marginal gap formation improving the continuity at the tooth–restorative material interface than conventional bulk-fill restorations. On the other hand, thermocycling.

WITHDRAWAL – Administrative Duplicate Publication: Vs-0 Correction Factors for Input Ground Motions used in Seismic Site Response Analyses

Input motions used in seismic site response analyses are commonly selected based on similarities between the shear wave velocity (Vs) at the recording station, and the reference depth at the site of interest (among other aspects such as the intensity of the expected ground motion). This traditional approach disregards the influence of the attenuation in the shallow crust on site response. Given that this attenuation (damping) can be characterized by the distance-independent high-frequency attenuation parameter 0, a Vs-0 correction framework for input motions is proposed to render them compatible with the assumed properties of the reference depth at the site. The proposed correction factors were applied to a subset of recordings from the KiK-net database, and compared to traditional deconvolution. Results indicate that Vs-0 corrected motions outperform deconvolved motions in the characterization of the spectral energy in the high-frequency range. However, motions recorded at sites with soft deposits are not good candidates for the Vs-0 correction approach. Vs-0 corrections also affect amplification functions which are important in the assessment of site-specific seismic hazards.

Modeling of kappa factor using multivariate adaptive regression splines: application to the western Türkiye ground motion dataset

The recent seismic activity on Türkiye’s west coast, especially in the Aegean Sea region, shows that this region requires further attention. The region has significant seismic hazards because of its location in an active tectonic regime of North–South extension with multiple basin structures on soft soil deposits. Recently, despite being 70 km from the earthquake source, the Samos event (with a moment magnitude of 7.0 on October 30, 2020) caused significant localized damage and collapse in the Izmir city center due to a combination of basin effects and structural susceptibility. Despite this activity, research on site characterization and site response modeling, such as local velocity models and kappa estimates, remains sparse in this region. Kappa values display regional characteristics, necessitating the use of local kappa estimations from previous earthquake data in region–specific applications. Kappa estimates are multivariate and incorporate several characteristics such as magnitude and distance. In this study, we assess and predict the trend in mean kappa values using three–component strong–ground motion data from accelerometer sites with known VS30 values throughout western Türkiye. Multiple linear regression (MLR) and multivariate adaptive regression splines (MARS) were used to build the prediction models. The effects of epicentral distance Repi, magnitude Mw, and site class (VS30) were investigated, and the contributions of each parameter were examined using a large dataset containing recent seismic activity. The models were evaluated using well–known statistical accuracy criteria for kappa assessment. In all performance measures, the MARS model outperforms the MLR model across the selected sites.

Assessing water quality in a distribution network based on hydraulic conditions

Abnormalities in hydraulic conditions inside a water distribution network are strongly related to the deterioration of drinking water quality. Leaking pipes and valves cause changes to the hydraulic conditions and allow the entry of impurities into the distribution system. Sudden flow and pressure shocks can detach soft deposits and biofilms from the pipe surface, resulting in deterioration of water quality. Online water quality measurements in a distribution network are scarce, but more common online flow and pressure measurements reveal the changes in hydraulic conditions in a distribution network and can be utilized to assess the water quality continuously and near real-time via modelling. Here, a data-driven model based solely on the online flow and pressure measurements in a distribution network for assessing the water quality at the end of an urban district metered area is presented. With the accuracy of R2 0.77, the developed data-driven model is able to assess the level of and the changes in potable water quality in a non-laborious and cost-effective way, also enabling proactive operations to ensure the distribution of high-quality drinking water to the consumers.

Construction of Buildings in Soft Clay Deposits: A Case Study in a Public School in Florianópolis/SC, Brazil

The gradual increase in the risks of constructions without structural planning in hillside areas characterizes the expansion of urbanization in Brazil. In this process of territorial occupation, constructions on soft clay soils represent significant structural hazards. This study aimed to evaluate structural instabilities in a public school in Florianópolis (SC, Brazil), using integrated geology, geotechnics, and geophysics data. This is a case study in an area characterized by the urbanization process of the West Side of the Costeira do Pirajubaé Massif. Geologically, the study area is composed of granitic rocks, soft clay deposits, and colluvial soils, in an environment of the upper third to the middle of the slope. For data analysis, geophysical, geotechnical, and geological methods were used. In the results, it was identified upstream colluvium, evidenced by the wide variety of soils (sandy, yellowish silt clay, of medium consistency), as well as gray clay deposits, ranging from very soft to hard, with distinct characteristics of the residual soils of the granitoid downstream, which are normally medium consistency brown to yellowish clays, expected for the B horizon. The results indicate a potential slip surface, which corresponds to a layer of soft clay deposits. Thus, it can be concluded that the observed instabilities, characterized by footing displacement, cracks, and subsidence demonstrate subsoil fragilities related to human interventions and the insufficiency of the drainage system, even when existing.