Trampling the Archaeological Record: An Experimental Study

1991 ◽  
Vol 56 (3) ◽  
pp. 483-503 ◽  
Author(s):  
Axel E. Nielsen

This paper reports on several experiments carried out to explore the transformations of the archaeological record affected by trampling. These transformations include changes in artifact distributions and formal alterations that should be taken into account when carrying out studies of activity areas. The experiments were made on dry, hard-packed surfaces and in the same sediments after a rain. The materials used were bones, obsidian flakes, sherds, and fragments of brick and wood. The analysis focuses on vertical displacement, horizontal displacement, and damage (breakage, microflaking, and abrasion), paying special attention to the response of the trodden substrate and its implications for the whole process. The interaction of trampling with other formation processes (e.g., maintenance) also is considered. The main patterns observed in the trampled materials are vertical and horizontal size sorting, and characteristic size distributions in sherds. These empirical generalizations are then integrated in a model that can help to identify trampled contexts and assess their potential for behavioral inference.

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Toshifumi Nogawa ◽  
Masayasu Saito ◽  
Naomichi Murashima ◽  
Yoshiyuki Takayama ◽  
Atsuro Yokoyama

Abstract Background Implant-supported removable partial dentures (ISRPDs) are an effective treatment for partially edentulous patients. ISRPDs improve patients’ satisfaction and oral function to a greater extent than RPDs by improving denture stability and enhancing support. However, the effect of a type of direct retainer on displacement of the abutment teeth and dentures in ISRPDs remains unclear. Therefore, we made a resin mandibular model of unilateral mandibular distal-extension partial edentulism for mechanical simulation and compared the dynamic behavior of the abutment teeth and the denture base among different tooth-borne retainers with various rigidities for RPDs and ISRPDs. Methods A resin mandibular model for mechanical simulation that had unilateral mandibular distal-extension edentulism and was missing the first molar, second molar, first premolar, and second premolar, and a denture fabricated from the patient’s computed tomography images were used. Three types of direct retainers with different connecting rigidities were evaluated. The vertical displacement of the denture base and buccal and lingual sides and the mesial displacement of the abutment teeth were measured. Results Regardless of the rigidity of the direct retainers and loading positions, the displacement of the denture bases in the ISRPDs was significantly smaller than that in the RPDs (P < 0.001). There was no significant difference in vertical displacement of the denture bases among direct retainers with various connecting rigidities in the ISRPDs. Conversely, horizontal displacement of the abutment teeth in both the RPDs and ISRPDs tended to be larger with the cone crown telescope, which has high rigidity, than with the cast cingulum rest and wire clasp, which have much lower rigidities. Conclusion Our results suggested that cast cingulum rest and wire clasps as direct retainers are appropriate ISRPDs to minimize denture movement and suppress displacement of the remaining teeth in patients with unilateral mandibular distal-extension partial edentulism.


1934 ◽  
Vol 24 (4) ◽  
pp. 345-384 ◽  
Author(s):  
Vincent P. Gianella ◽  
Eugene Callaghan

Summary The Cedar Mountain, Nevada, earthquake took place at about 10h 10m 04s p.m., December 20, 1932. It was preceded by a foreshock noted locally and followed by thousands of aftershocks, which were reported as still continuing in January 1934. No lives were lost and there was very little damage. The earthquake originated in southwest central Nevada, east of Mina. A belt of rifts or faults in echelon lies in the valley between Gabbs Valley Range and Pilot Mountains on the west and Cedar Mountain and Paradise Range on the east. The length of this belt is thirty-eight miles in a northwesterly direction, and the width ranges from four to nine miles. The rifts consist of zones of fissures which commonly reveal vertical displacement and in a number of places show horizontal displacement. The length of the rifts ranges from a few hundred feet to nearly four miles, and the width may be as much as 400 feet. The actual as well as indicated horizontal displacement is represented by a relative southward movement of the east side of each rift. The echelon pattern of the rifts within the rift area indicates that the relative movement of the adjoining mountain masses is the same. The direction of relative horizontal movement corresponds to that along the east front of the Sierra Nevada at Owens Valley and on the San Andreas rift.


2021 ◽  
Vol 11 (16) ◽  
pp. 7577
Author(s):  
Lin Wu ◽  
Xiedong Zhang ◽  
Wei Wang ◽  
Xiancong Meng ◽  
Hong Guo

Train vibration from closely aligned adjacent tunnels could cause safety concerns, especially given the soaring size of the tunnel diameter. This paper established a two-dimensional discrete element model (DEM) of small (d = 6.2 m) and super-large (D = 15.2 m) diameter cross-river twin tunnels and discussed the dynamic characteristics of adjacent tunnels during the vibration of a train that runs through the tunnel at a speed of 120 km/h. Results in the D tunnel showed that the horizontal walls have the same horizontal displacement (DH) and the vertical walls have the same vertical displacement (DV). The stress state of the surroundings of the D tunnel is the decisive factor for DH, and the distance from the vibration point to the measurement point is the decisive factor for DV. Results in the comparison of the d and D tunnels showed that the D tunnel is more stable than the d tunnel with respect to two aspects: the time the tunnel reaches the equilibrium state and the vibration amplitude of the structure’s dynamic and static responses. The dynamic characteristic of the d and D tunnel is significantly different. This research is expected to guide the design and construction of large diameter twin tunnels.


2001 ◽  
Vol 34 (4) ◽  
pp. 1405
Author(s):  
Γ. Δ. ΔΑΝΑΜΟΣ ◽  
Ε. Λ. ΛΕΚΚΑΣ ◽  
Σ. Γ. ΛΟΖΙΟΣ

The Jan. 26, 2001, Ms=7.7 earthquake occurred in Gujarat region of W. India, which lies 200-400 Km away from the active plate boundary zone, between the Indian subcontinent and the Asian plate, along the India-Pakistan border and the Himalayan belt. An Ms=7.7±0.2 earthquake also occurred in the same region in 1819. A zone of co-seismic E-W surface ruptures, 30-40 Km long and 15-20 Km wide, observed near the epicentral area and seems to be associated with pre-existing reverse faults and thrust folds, which were partially reactivated during the recent earthquake. Except the reverse vertical displacement a significant right lateral displacement was also observed along these E-W surface ruptures. This Ms=7.7 seismic event has been also accompanied by a large scale flexural-slip folding, as the absence of significant co-seismic fault displacement and fault scarp shows. This type of compressional tectonic deformation is also confirmed by the focal mechanism of the earthquake and the seismo-tectonic "history" of the area. The NW-SE open cracks, also observed along the same zone, are associated with the right lateral horizontal displacement of the reactivated fault (or branch faults) and the development of local extensional stress field in the huge anticlinic hinges of the co-seismic flexural-slip folds. A large number of ground ruptures, failures and open cracks are also associated with extensive sand boils, liquefaction phenomena and lateral spreading.


2013 ◽  
Vol 405-408 ◽  
pp. 428-433
Author(s):  
Fu Yong Chu ◽  
Jun Gao Zhu

Abstract: The stress and deformation of rock-fill dam with asphalt concrete core wall founded on deep overburden is calculated and analyzed by Duncan E-ν model and double-yield-surface model through three-dimensional finite element method. The stress and deformation of dams in water storage period is compared by the two models, the results show that the deformation distribution of dam core via two different models are coincide one another. The horizontal displacement and vertical displacement of rock-fill dam with asphalt concrete core wall by double-yield-surface model is smaller than which by Duncan E-ν model in the period of water storage. Furthermore, the horizontal displacement and vertical displacement by double-yield-surface model, which are close to the practical test data through the deformation via two models are in good agreement. The analysis of core-wall stress via double-yield-surface model is more reasonable than the Duncan E-ν model. The analysis result of resisting hydraulic fracturing of core dams by DuncanE-ν model is coincide which of core dams by double-yield-surface model.


2012 ◽  
Vol 170-173 ◽  
pp. 1005-1012
Author(s):  
Lin You Pan ◽  
Xiao Bing Li ◽  
Chuang Yu ◽  
Fu Xue Sun

In view of Wenzhou saturated super soft soil, This article studied the influence of different soil parameters for the shaft excavation construction and the stratum displacement change law by using Plaxis finite element software, according to the data obtained in field tests. The considered factors included the lateral brace stiffness, the stiffness of the underground diaphragm wall, and the surrounding soil disturbance. The calculation results provided much important engineering information, such as the horizontal displacement nephogram, the vertical displacement nephogram and the total displacement incremental vector diagram of each construction steps, which can be referred for the construction of the similar underground projects in soft soil areas.


2018 ◽  
Vol 55 (1) ◽  
pp. 7-14
Author(s):  
Fengshan Ma ◽  
Hongyu Gu ◽  
Jie Guo ◽  
Rong Lu

Sanshandao Gold Mine is the first and largest mine operating below sea level in China. Mining has been practiced in this region for at least 25 years. In recent years, buildings above the mining area have been extensively damaged. GPS (with 315 monitoring points) was used to monitor the ground deformation since 2009. Ground deformation induced by mining is much more complex in metal mine than that in coal mines due to the well-developed joints, high tectonic stress and several intersecting faults. All of the factors are analyzed in this study. The results show that discontinuous deformation has occurred on the surface because of the sliding to F3 (name of fault), and there are two motion patterns of F3 during the mining process. Additionally, joints in rock masses with steep dip angles contribute to the vertical displacement and joints with shallow dip angles contribute to the horizontal displacement. Meanwhile, high tectonic stress dramatically enlarges the scale of ground deformation, especially with respect to the horizontal displacement. This deformation results in a striped formation of compressed and stretched regions. Additionally, high-risk and potential risk areas are identified in this study. Finally, the successive data measured since 2009 can contribute to a deeper understanding of ground deformation in metal mine.


2020 ◽  
Vol 14 (04) ◽  
pp. 2050018 ◽  
Author(s):  
Chentong Hu ◽  
Yifan Wu ◽  
Chao An ◽  
Hua Liu

Tsunamis are generated primarily by the vertical displacement of the seafloor if the seafloor is flat. If the seafloor is slanted, the horizontal motion also contributes to the generation of tsunamis. A previous study proposed that such effects can be estimated by simply calculating the elevation of water due to the horizontal displacement of the slope. Two more studies later argued that the horizontal motion also results in horizontal momentum of the water, which amplifies the tsunami generation. In this study, we numerically simulate the tsunami generation process of flat and sloping seafloor. It is found that, for the flat seafloor, the initial water elevation equals the vertical seafloor displacement. For the sloping seafloor, the initial water elevation deviates from the vertical seafloor displacement, and the difference can be accurately evaluated by the horizontal seafloor displacement. Thus, the initial horizontal momentum of the water is negligible for tsunami generation.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peisen Wang ◽  
Hongyan Ding ◽  
Puyang Zhang

The differences in development and situation of karst caves lead to two kinds of karst caves, and the karst cave may be on the pile side or at the pile bottom, which has a different influence on the bearing capacity of pile foundation. The paper presents a numerical analysis of the influence of karst caves at pile side on the bearing capacity of super-long pile foundation in karst areas. According to the size of pile foundation of a real bridge project, this paper modelized karst caves and investigated the karst cave from the effect of length, height, and thickness of roof on horizontal and vertical bearing capacity of pile foundation. The main conclusions can be drawn as: when the horizontal displacement at the top of pile foundation is greater than 0.05 m, the horizontal load is correlated positively with the length of karst cave; when the vertical displacement is greater than 0.07 m, the vertical load is correlated negatively with the thickness of the roof of karst cave. However, the height of karst cave has little effect on the bearing capacity; also the existence of karst cave has little influence on the dynamic response of pile foundation. The results of this study can be important with reference to the design and construction of pile foundations in karst areas.


2011 ◽  
Vol 368-373 ◽  
pp. 850-853
Author(s):  
Hai Wang Li ◽  
Jing Jing Guo ◽  
Jing Liu

In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 60 m span and 0.4 rise-span ratio is carried out under earthquake wave with SAP2000. In the analyses, the geometric and material nonlinear effects are considered at the same time based on the plastic-hinge theory. Under the action of EL wave with the peak increasing gradually, its elasto-plastic dynamic responses have been obtained. The results show that its failure mode under the earthquake action is elasto-plastic dynamic buckling; that its critical peak acceleration of EL earthquake wave when applied in horizontal direction is 808.5 gal, and is 789.0 gal when applied in vertical direction; The ratio of its maximal node horizontal displacement and its structural height is 1/259, and its displacement ductility coefficient is 1.071; The ratio of its maximal node vertical displacement and its structural span is 1/736, and its displacement ductility coefficient is 1.105.


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