Hydraulic Shear Research Articles

Experimental Study on Dynamic Performance of Plain Concrete and Lightweight Aggregate Concrete under Uniaxial Loading

To examine the uniaxial behaviors of plain concrete and lightweight aggregate concrete under dynamic loadings, the plain concrete specimens and lightweight aggregate concrete specimens prepared by shale ceramsite were designed and tested under the loading strain rate range of 10−5/s–10−2/s. The hydraulic servo machine and shear device were applied to conduct the uniaxial compression, splitting tensile, and shear tests of both types of concretes, and the failure modes and stress-strain curves of two concrete at varying loading conditions were obtained from the test results. By comparing and analyzing the test results, the following conclusions are obtained: the failure of cementing layer occurs in plain concrete at low strain rates, while some coarse aggregates are damaged at high strain rates, but the failure of lightweight aggregate concrete is caused by the fracture of shale ceramsite at all strain rates. As the loading strain rate increases, the uniaxial compressive strength, splitting tensile strength, and shear strength of plain concrete and lightweight aggregate concrete are significantly increased, with the improved percentages of 35.63%, 43.75%, and 41.29% for plain concrete and 44.87%, 55.97%, and 49.44% for light aggregate concrete, respectively. For both types of concrete, the increase of strain rate has a more significant effect on the increase of splitting strength than compressive strength. In addition, the strain rate effect on the strength of lightweight aggregate concrete is significantly higher than that of plain concrete. The dynamic increase factor of peak stress of both concretes under uniaxial loadings is linearly related to the dimensionless logarithmic values of the strain rate. Based on the test results and analysis, two different relationship expressions between compressive strength, splitting tensile strength, and shear strength of two types of concretes are proposed, and the dynamic effects of concrete are explored from the perspective of the damage mechanism. This study is meaningful to the engineering applications and development of plain concrete and lightweight aggregate concrete.

Geometric Optimization of an Extracorporeal Centrifugal Blood Pump with an Unshrouded Impeller Concerning Both Hydraulic Performance and Shear Stress

Centrifugal blood pumps have provided a powerful artificial support system for patients with vascular diseases. In the design process, geometrical optimization is usually needed to acquire a more biocompatible model for clinical uses. In the current paper, we propose a method for multi-objective optimization concerning both the hydraulic and the hemolytic performances of the pump based on the near-orthogonal array in which the traditional hemolysis index (HI) is replaced with the maximum scalar shear stress criteria to reduce the computation load. The method is demonstrated with the optimization of an extracorporeal centrifugal blood pump with an unshrouded impeller. CFD studies on the original and nine modified pump models are carried out. The calculated hydraulic performances of the optimized model are also compared against the experiments for validation of the numeric method, with an error of 3.6% at the original design point. The resulting blood pump with low maximum scalar shear stress (132.2 Pa) shows a low degree of calculated HI (1.69 × 10−3).

A case study of vertical hydraulic fracture growth, stress variations with depth and shear stimulation in the Niobrara Shale and Codell Sand, Denver-Julesburg Basin, Colorado

We have carried out a geomechanical study of three wells, one each in the Niobrara A, Niobrara C, and Codell Sandstone to investigate how the state of stress and stress variations with depth affect vertical hydraulic fracture growth and shear stimulation of preexisting fractures. We determine that the higher magnitudes of measured least principal stress values in the Niobrara A and C shales are the result of viscoplastic stress relaxation. Using a density log and a vertical transverse isotropy velocity model developed to accurately locate the microseismic events, we theoretically calculated a continuous profile of the magnitude of the least principal stress with depth. This stress profile explains the apparent vertical hydraulic fracture growth as inferred from the well-constrained depths of the associated microseismic events. Finally, we determine that because of the upward propagation of hydraulic fractures from the Niobrara C to the Niobrara A, the latter formation experienced considerably more shear stimulation, which may contribute to the greater production of oil and gas from that formation.

Effect of Unimodal and Bimodal Soil Hydraulic Properties on Slope Stability Analysis

Rainfall infiltration is the primary triggering factor of slope instability. The process of rainfall infiltration leads to changes in the water content and internal stress of the slope soil, thereby affecting slope stability. The soil water retention curve (SWRC) was used to describe the relationship between soil water content, matric suction, and the water retention characteristics of the soil. This characteristic is essential for estimating the properties of unsaturated soils, such as unsaturated hydraulic conductivity function and shear strength. Thus, SWRC is regarded as important information for depicting the properties of unsaturated soil. The SWRC is primarily affected by the soil pore size distribution (PSD) and has unimodal and bimodal features. The bimodal SWRC is suitable for soils with structural or dual-porous media. This model can describe the structure of micropores and macropores in the soil and allow the hydraulic behavior at different pore scales to be understood. Therefore, this model is more consistent with the properties of onsite soil. Few studies have explored the differences in the impact of unimodal and bimodal models on unsaturated slopes. This study aims to consider unimodal and bimodal SWRC to evaluate the impact of unsaturated slope stability under actual rainfall conditions. A conceptual model of the slope was built based on field data to simulate changes in the hydraulic behavior of the slope. The results of seepage analysis show that the bimodal model has a better water retention capacity than the unimodal model, and therefore, its water storage performance is better. Under the same saturated hydraulic conductivity function, the wetting front of the bimodal model moves down faster. This results in changes in the pressure head, water content, and internal stress of the soil. The results show that the water content and suction stress changes of the bimodal model are higher than those of the unimodal model due to the difference in water retention capacity. Based on the stability of the slope, calculated using the seepage analysis, the results indicate that the potential failure depth of the bimodal model is deeper than that of the unimodal model.

Enhancing stability of aerobic granules by microbial selection pressure using height-adjustable influent strategy

Optimizing granules size distribution is critical for both reactor performance and stability. In this research, an optimal size range of 1800 to 3000 μm was proposed regarding mass transfer and granules stability based on granules developed at DO around 8.0 mg L−1 with the feed COD:N:P at 100:5:1. A height-adjustable influent strategy was applied to facilitate the nutrient storage of granules at optimum size range via microbial selective pressure. Results suggested insufficient hydraulic shear stress led to overgrowth of granules size. High abundance of filamentous bacteria (Thiothrix sp.) was observed in oversized granules, which detached and affected the remaining granules, resulting in severe sludge bulking. Strong hydraulic shear stress suppressed uncontrolled growth of granules. However, fewer abundance of simultaneous nitrification and denitrification (SND) bacterium was acquired, which led to unfavored SND effect and total nitrogen (TN) removal efficiency. The height-adjustable influent strategy facilitated the poly-β-hydroxybutyrate (PHB) storage of granules at optimum size range, while limiting the overgrowth of granules size. Additionally, more than 87.51% of total granules situated in optimal sizes range, which led to higher abundance of SND bacterium and higher TN removal efficiency.

Experimental Study of Hydraulic Sealability and Shear Bond Strength of Cementitious Barrier Materials

Abstract In this experimental study, two different cementitious materials, including (i) a class of expansive cement currently used for plug and abandonment (P&A) operations and (ii) a non-cement-based naturally occurring rock, known as geopolymer, are selected to examine the hydraulic bond strength and shear bond strength. Clean machined steel and rusty corroded steel were selected to represent the casing. The test samples were cured at 90 °C considered as bottom-hole static temperature (BHST) and under elevated pressure of 17.2 MPa for 1 week. The hydraulic sealability of the barrier materials tested up to 3.4 MPa of differential pressure. The results indicated that additives used in slurry preparation impact the hydraulic sealability of the material. Additionally, the rusty corroded steel provided a better hydraulic sealability comparing to the clean machined steel for the same cementitious material. The shear bond strength test was performed by running the push-out test. According to the present test observations, no correlation was found between the shear bond and hydraulic bond strength of different barrier materials. The geopolymer showed the lowest shear bond strength, while it provided the highest hydraulic sealability.

Evaluating the hydromechanical responses of seabed–pipelines with rotated anisotropic heterogeneous seabed properties

Seabed sediments are inherently heterogeneous and present different fabric patterns including rotated anisotropy. This work aims to investigate the effects of rotated anisotropy in seabed properties on the hydromechanical responses of seabed and pipelines. Rotated anisotropic seabed property fields (e.g., hydraulic conductivity and shear modulus fields) are generated using the random field theory, and are then coupled with finite element models to simulate the hydromechanical responses of seabed–pipelines under dynamic nonlinear wave-induced loadings. Monte Carlo simulations are performed to approach a probabilistic analysis of the effects of heterogeneous seabed fields. The pore pressure, liquefaction, seabed displacement, and pipeline stress are analyzed for systematic varying rotation angles. The results show that the upper bounds of the liquefied area would decrease by about 15% and 8% with increasing rotated anisotropy in the hydraulic conductivity and shear modulus fields, respectively. For rotated anisotropic shear modulus fields, the von Mises stress is minimum when the rotation angle is 45∘. The transverse anisotropy in hydraulic conductivity or shear modulus is the most unfavorable situation, the results of which could be relied upon for a conservative design if the rotated anisotropy of a seabed property is unknown in a field project.

Continuous flow reactors for cultivating aerobic granular sludge: configuration innovation, principle and research prospect

AbstractEfficient start‐up, cultivation and maintenance of aerobic granular sludge (AGS) in continuous flow reactors (CFRs) is critical for its full‐scale application in wastewater treatment plants (WWTPs). The successful implementation of AGS under continuous flow condition depends on the configuration of CFR that provides the selective pressures and hydraulic shear force (HSF) to sludge required for rapid granulation. Important progress has been witnessed with respect to CFR configurations in recent decades for in‐situ granulation of aerobic sludge. This review summarized the difficulties of granulation during continuous flow, as well as the reactor configuration, granulation mechanism and the AGS characteristics, along with the future research prospects. It is of significance to promote the innovation of continuous flow configuration in order to realize the AGS application in mainstream WWTPs in the future. © 2021 Society of Chemical Industry (SCI).

Encapsulation of microorganisms for simultaneous nitrification and denitrification in aerobic reactors

A special denitrifying capsule that was designed according to the theory of maldistribution of DO (dissolved oxygen) for simultaneous nitrification and denitrification (SND) in an aerobic reactor was prepared by an encapsulation technique. The morphology of the denitrifying capsule and its SND performance in an aerobic reactor used for treating synthetic low C/N wastewater were systematically investigated. The spherical capsule comprised a porous membrane, denitrifying active sludge and semen litchi powder, which were cohered together by a physical method. Well-shaped pores were distributed in the membrane and the average pore diameter was approximately 0.25 µm. Circular pores were present in the cross section of the membrane, and the thickness of the membrane ranged from 95.0 µm to 120.0 µm. After 7 days of acclimation, the denitrifying capsule showed good SND performance in an aerobic reactor with a DO concentration of 5.09 mg/L. The NH4+-N concentration of 51.09 mg/L was removed completely after 8 h, the effluent dissolved inorganic nitrogen (DIN) concentration decreased to 6.11 mg/L, the SND ratio reached to 91.6% at 6 h, and finally decreased to 2.09 mg/L at 15 h and could also reach 98.91%. The influent of NH4+-N loading had little effect on the nitrogen removal performance. And decreased of air input induced lower hydraulic shearing force compared to reactors with higher DO had a little effect on the diffusion and mass transfer of NO3--N. With this core shell structure denitrifying capsule, it was easy to achieve SND without controlling the DO concentrations at low levels or using intermittent aeration.

Visualizing, quantifying, and controlling local hydrodynamic effects on biofilm accumulation in complex flow paths

Complex flow paths (CFPs) are commonly applied in precision equipment to accurately supply controllable fluids with designed structures. However, the presence of biofilms in CFPs causes quite a few unwanted issues, such as bio-erosion, clogging, or even health risks. To date, visualizing and quantifying the interaction between biofilm distribution and local hydrodynamics remains difficult, and the mechanism during the process is unclear. In this paper, the remodeling simulation method (3D industrial computed tomography scanning-inverse modeling-numerical simulation) and 16S rRNA high-throughput sequencing were integrated. The results indicated that local hydrodynamic characteristics significantly affected biofilm thicknesses on CFP surfaces (relative differences of 41.3–71.2%), which inversely influenced the local turbulence intensity. The average biofilm thicknesses exhibited a significant quadratic correlation with the near-wall hydraulic shear forces (r > 0.72, p < 0.05), and the biofilm reached a maximum thickness at 0.36–0.45 Pa. On the other hand, the near-wall hydraulic shear forces not only affected microbial community characteristics of biofilms, but they also influenced the number of microorganisms involved, which determined the biofilm accumulation thereafter. The PHYLUM Firmicutes and Proteobacteria were the dominant bacteria during the process. The results obtained in this paper could provide practical conceptions for the targeted control of biofilms and put forward more efficient controlling methods in commonly applied CFP systems.

Stiffness, compressibility, and hydraulic conductivity of compacted soil mixtures submitted to acidic percolation

Abstract The inadequate disposal of hazardous solid waste has become a potential issue, mainly because of the impacts on the environment and human health. This occurs mainly through the contamination of subsurface soil and groundwater by leachates, which are often of the acidic constitution. To prevent such situations, the study of more efficient waste containment techniques has become opportune. In this way, this work was aimed to investigate the mechanical and hydraulic behavior of compacted clayey soil, with and without the addition of Portland cement (0 and 2%), submitted to the action of a sulfuric acid solution (2% volume concentration) and to a constant static vertical load (280 kN/m2), aiming at its prospective application as containment barrier. The experimental program comprised a few tests performed in an instrumented rigid-wall permeameter, during which the variations in hydraulic conductivity, shear modulus, and settlements were measured. The results showed that the hydraulic conductivity increased with cement addition when only water was percolated. During the acidic percolation, however, a reduction was observed only for the cemented soil. The acidic attack caused, almost instantaneously, an increase in the settlement rate and a reduction in stiffness, although a trend of stabilization was observed afterward.

Heyde’s syndrome as a rare cause of gastrointestinal bleeding in aortic stenosis patients

Heyde’s syndrome is one of the causes of gastrointestinal bleeding in patients with heart disease. It is characterized by the acquired destruction of high molecular weight multimers of von Willebrand factor due to high hydraulic shear stress on the aortic valve in severe stenosis, followed by gastrointestinal bleeding due to angiodysplasias. Management of such patients is a complex and relevant problem. The central method of treatment for Heyde’s syndrome is aortic valve replacement, which reduces the risk of recurrent gastrointestinal bleeding in more than 90% of patients.

Experimental investigation on seepage erosion of the soil–rock interface

Internal erosion under seepage flow affects the hydraulic and mechanical behavior of the soil, which is one of the most important factors of geological disasters. Due to that the soil–rock interface can be the potential preferential seepage channels commonly, the characteristics of erosion are more significant and hazardous at the soil–rock interface. In this study, a series of laboratory experiments are performed to investigate the failure mechanism and evolution of interfacial seepage erosion. The influences of two essential influence factors (i.e., the confining pressure and the roughness of the interface) are investigated by comparing the seepage velocity, hydraulic conductivity, failure hydraulic gradient, and failure hydraulic shear stress in experiments. Furthermore, the failure pattern of interfacial seepage erosion is particular investigated by the CT scanning. The interfacial seepage erosion tests indicate that the interfacial seepage erosion shows a three-phase progressive failure as the hydraulic gradient increases and the hydraulic conductivity decrease with the progress of suffusion in the initiation phase. The increase of confining pressure leads to the increase of failure hydraulic gradient. The results of CT scanning show that the roughness of the soil–rock interface significantly affects the size and shape of resulting zone of erosion.

Role of shear stress in biological aerated filter with nanobubble aeration: Performance, biofilm structure and microbial community

This study comprehensively investigated the role of shear stress in a biological aerated filter under nanobubble aeration with the operation of an internal reflux and mechanical bubbling, where nanobubbles provide an opportunity to separately assess the effect of the hydraulic shear stress and aeration on the properties of the biofilms. Shear stress optimized the oxygen distribution, which improved the dissolved oxygen of the effluent three- and four-fold through reflux and mechanical bubbling, respectively. Proper shear stress enhanced the spatial development of the biofilms and promoted the activity and stability of nanobubble-aerated biofilms, achieving a sufficient contaminant removal efficiency that meets the local standard. Shear stress and aeration individually regulated the functional pathways and improved the development of the biofilm structure and the performance. The results indicate that nanobubble is a promising aeration technology when accompanied by a shearing strategy.

Flow hydraulic characteristics and dynamic erodibility of saline-sodic soil slopes for coastal areas under simulated rainfall conditions

ABSTRACT Tidal flat reclamation generates several excavated saline-sodic soil slopes. However, there are limited studies on the hydraulic flow characteristics and dynamic erodibility of saline-sodic soil slopes. This study was conducted to quantify the effects of the soil bulk density (1.35 and 1.40 g cm−3), rainfall intensity (85, 110, and 125 mm h−1), and slope gradient (11°, 22°, and 35°) on the hydraulic characteristics and soil erodibility of saline–sodic soil slopes under simulated rainfall conditions. The mean sediment loss significantly increases with the slope gradient (pr = 0.9, p < 0.01), rainfall intensity (pr = 0.6, p < 0.05), and soil bulk density (pr = 0.6, p < 0.05). The hydraulic shear stress (τ) and stream power (ω) are good sediment loss predictors for all soil bulk densities (R2 = 0.4 and 0.6). The stream power equation SL = Kω (ω − ωcr ) outperforms both hydraulic shear stress equations [SL = Kτ (τ − τcr )3/2; SL = Kτ (τ − τcr )]. In most cases, the soil erodibility exponentially increases to a maximum and then exponentially decreases (R2 > 0.6). Consequently, the dynamic changes in the saline-sodic soil erodibility during a rainfall event cannot be neglected.

The simultaneous recruitment of anammox granules and biofilm by a sequential immobilization and granulation approach

Anaerobic ammonium oxidation (anammox) is an important pathway in the nitrogen cycle and for autotrophic nitrogen removal of wastewater. However, the slow granulation or biofilm formation of anammox bacteria in a continuous-flow reactor without anammox inoculum is still a challenge. To accelerate granulation or biofilm formation, an approach of sequential immobilization and granulation of anammox (SIGA) and an internal circulation immobilized blanket (ICIB) with non-granular activated sludge inoculum was investigated. Pre-immobilizing the biofilm with carriers showed higher efficiencies of nitrite removal and enrichment of Candidatus Kuenenia than anaerobic sludge without immobilization. An ICIB with pre-immobilized anaerobic biofilm and an up-flow anaerobic sludge bed (UASB) with pre-acclimated anaerobic sludge were operated for 180 d. The ICIB reactor achieved a nitrogen removal rate of 1.11 kg·N/(m3·d) whereas the UASB reactor only obtained 0.29 kg·N/(m3·d). Illumina HiSeq sequencing of 16S rRNA gene amplicons indicated that the relative abundance of anammox bacteria (Candidatus Kuenenia, Candidatus Brocadia, and Candidatus Jettenia) achieved 42.5–50.6% in biofilm and 45.3–47.1% in granules in the ICIB reactor. By contrast, no anammox bacteria were enriched in the sludge of the UASB reactor. These findings showed that the granulation and the biofilm formation of abundant anammox bacteria occurred in a single ICIB. The anammox biofilm and internal circulation facilitate the granulation of anammox bacteria, as the planktonic anammox cells escaped from the biofilm on the carrier provides parent cells for the formation of anammox granules under suitable hydraulic shear conditions. This study provides a new strategy for a faster start-up of anammox using activated sludge inoculum based on ICIB and SIGA.

Evaluation of the quality of cultivated-layer soil based on different degrees of erosion in sloping farmland with purple soil in China

The assessment of cultivated-layer soil quality (CLSQ) is important for improving crop growth capacity and is the premise for taking effective remedial measures. The cultivated-layer soil quality index (CLSQI) is a significant tool for evaluating CLSQ. This study aims to select the most effective indicators to construct a minimum data set (MDS) for soil in erosion-impacted hilly areas with purple soil in China and to analyse the association between CLSQ and the erosional environment. Taking the erosion of purple soil of sloping farmland in China as the focus of this study, different combinations of scoring methods, indicators, and data set methods were compared. In this study, the MDS is constructed by principal component analysis (PCA) in conjunction with the norm value, and the accuracy of the MDS is verified by the Nash effective coefficient. Furthermore, the nonlinear scoring (NLS) method is used to normalize the indicator data and then assess the CLSQ of soils with different degrees of erosion using the CLSQI. The results showed the following. 1) The soil indicators significantly varied under the different erosion degrees: the soil productivity showed a decreasing trend with increasing erosion, while the soil anti-erosion ability and tillage performance showed increasing trends with increasing erosion. 2) For the study area, the generated MDS included saturated hydraulic conductivity, bulk density, shear strength, penetration resistance and available phosphorus. 3) The CLSQI-NLS evaluation method was most suitable for this research topic, and combined with the MDS indicators, it could be used to accurately evaluate the CLSQ. 4) As the erosion degree intensified, the CLSQI showed an obvious decreasing trend, and the CLSQI under soil erosion of 20 cm (S-20, 0.393) was significantly lower than that under other erosion degrees, indicating that soil erosion gradually reduced the CLSQ. After the cultivated-layer soil was eroded and the subsoil was converted to cultivated-layer soil, the soil quality obviously decreased. The indexing approach used in this study provides a practical and time- and cost-effective method for the quantitative evaluation of CLSQ for erosion-prone soil in hilly areas with purple soil worldwide.

Oil film characteristics and flow field analysis of asymmetrical hydrostatic support structure with full hydraulic fixed-length shear servo cylinder

The heavy-duty servo cylinder is the main actuator of the full-hydraulic fixed-length shear. The cylinder requires horizontal articulated mounting for accurate curve forces. The output of the curvilinear force causes the piston rod to be subjected to a dynamic bias load, and the presence of the bias load adversely affects the servo cylinder seal structure. In this paper, an asymmetric hydrostatic support structure is designed in the guide sleeve for the bias load problem of the servo cylinder, and the anti-offset capacity of the structure is theoretically studied. The oil film characteristics and oil film stiffness of the structure are deduced and analyzed. Fluent software is used to simulate, and then analyze the influence of inlet pressure, piston rod speed, eccentricity and partial load on the performance of asymmetric static pressure bearing oil film. Asymmetrical hydrostatic support structure servo hydraulic cylinder test bench is built for anti-bias load performance and friction performance experiments. The research results show that the new asymmetric hydrostatic support structure has a good effect on balancing the dynamic partial load, effectively reducing the friction of the servo cylinder and making the automatic alignment of the piston rod and the guide sleeve, which proves that the technology can be effective, increase the service life of the servo hydraulic cylinder and then improve the overall efficiency of the full hydraulic dividing shear, while broaden the application field of the heavy duty servo cylinder.

Hydromechanical analysis of the second hydraulic stimulation in well PX-1 at the Pohang fractured geothermal reservoir, South Korea

In this study, we investigate numerically the hydro-mechanical behavior of fractured crystalline rock due to one of the five hydraulic stimulations at the Pohang Enhanced Geothermal site in South Korea. We use the commercial code FracMan (Golder Associates) that enables studying hydro-mechanical coupled processes in fractured media in three dimensions combining the finite element method with a discrete fracture network. The software is used to simulate fluid pressure perturbation at fractures during hydraulic stimulation. Our numerical simulation shows that pressure history matching can be obtained by partitioning the treatment into separate phases. This results in adjusted stress-aperture relationships. The evolution of aperture adjustment implies that the stimulation mechanism could be a combination of hydraulic fracturing and shearing. The simulated extent of the 0.01 MPa overpressure contour at the end of the treatment equals to ∼180 m around the injection point.

Investigation and study of hydraulic fracturing and the efficiency of this in oil reservoirs naturally fractured and caven

Hydraulic fracture operation is one of the key technologies for the development of caven reservoirs. Modeling of hydraulic fracture processes to factors such as Situation of tensions, Shear strength and Orientation of natural fractures in the reaction(In particular, the potential for opening cracks in areas that are growing along the path of a hydraulic fracture) And also the length and height of the hydraulic fracture. Due to the presence of natural fractures with diffuse penetration and different orientations, the operation is complicated in caven reservoirs. For this purpose, two numerical methods are proposed for simulating the hydraulic fracture in caven reservoirs.In this paper, the hydraulic fracture model is considered in terms of the state of tensions, On the reaction between the hydraulic fracture and the natural fracture (45 °) And also the effect of length and height of hydraulic fracture, Developed and how to distribute induced stress around the well, In order to determine the direction in which the hydraulic fracture is formed in that direction The finite difference method and theindividual element for numerical solution are used and simulated.An inverse suction is an important parameter And in the operation of the hydraulic fracture will reduce production,This simulation is being studied. In every length of the hydraulic fracture, The rate of production is measured and the causes of changes in the input rate to the wells are discussed based on the natural fractures cut by the hydraulic fracture and the induction of the fracture. Finally, it can be seen that the optimum hydraulic fracture time will be The hydraulic fracture is able to connect natural fractures with large and large streams And finally, it is connected to the well, and there is a fundamental difference between the tensile and shear opening. The analyzes indicate that the growing hydraulic fracture, the tensile and shear stresses applied to the natural fracture.