Table of Contents
Assignment: Slide Effects On Structures
Assignment: Slide Effects On Structures
The effects of the landslide have been progressive, first causing damage and then destruction of homes and other structures. Many roads in the area are buckled and broken, requiring repeated repairs. By 1961, more than 150 homes had been destroyed or seriously damaged by the slide. Since then, many additional homes have been affected to some degree, and Palos Verdes Drive has been in constant need of repair. All underground utilities have been placed in above-ground steel pipes with flexible couplings.
Albers V. County Of Los Angeles
Affected homeowners filed suit in 1961 against the County of Los Angeles in a successful effort to obtain compensation for their losses, which amounted to nearly $10 million in 1960 dollars. The suit charged the county with liability based on negligence for the construction of Crenshaw Boulevard, which added weight to the upper slopes of the slide mass in the form of artificial fill. Although negligence could not be established, the county was found liable by the presiding judge using inverse condemnation.
Arguments by experts for the county brought several facts to light that were ultimately ignored in the judgment. These included: (1) the amount of artificial fill used in constructing Crenshaw Boulevard equaled only 0.5 percent of the total landslide mass in terms of weight, (2) the water added through septic system discharge and lawn irrigation probably caused groundwater levels in the slide mass to rise, and (3) detergents in the septic system effluent would be expected to have a negative effect on the strength of saturated bentonite clays.
Corrective Actions
An early attempt to prevent further slope movement was made by installing precast concrete pins through the slide mass in 1957. These pins, measuring 1.2 m (4 ft) in diameter and 6 m (20 ft) in length, extended 3 m (10 ft) into the underlying bedrock. Initially they slowed the rate of slope movement by 50 percent; however, after five months, the pins failed and movement accelerated.
The first of a three-phase stabilization project involved the installation of eight dewatering wells in the slide mass during the mid-1980s. Phase 2, completed during the late 1980s, included road relocations, surface drainage improvements, regrading the seaward side of the slide mass, and the addition of five more wells. In the early 1990s, revetments were placed at the base of the bluffs to protect them from wave erosion. Following the completion of this third phase, parts of the landslide were largely stabilized.
Questions
- If you were the judge, who do you think is responsible:
A. the County for its negligence,
B. the homeowners who chose to build their houses on the edge of a bluff, or
C. both parties share equal responsibility?Explain your reasoning to the rest of the court.
- How would the construction of Crenshaw Boulevard differ from the earlier construction of houses in terms of its ability to trigger a landslide?
- What do the successes of various corrective actions taken here suggest was/ were the cause(s) of the landslide?
REFLECTION
Question
- In Florida, king tides, storm surges, and heavy rains can cause some streets in Miami Beach to flood. It can shut down many businesses and deter tourism. How could the Portuguese Bend case study relate to the coastal flooding in Florida?
Note: Did you remember to answer all 10 questions with at least three complete sentences (36-42 words per answer)?
