HILL STREET BLUES

By ROBERT OURLIAN

Aug. 12, 1998 12 AM PT

TIMES STAFF WRITER

People with biblical powers can move mountains. It may take almost as much force to keep one in place.

When a 500-foot hillside supporting part of the upscale Niguel Summit development in Laguna Niguel gave way in March, destroying houses and condos and condemning others to eventual destruction, experts crawled across the fractured slope, trying to decide how to keep it from moving any more.

Now, the first phase of a possible solution is going in: 64 underground concrete pillars, each sunk about 110 feet until it is entrenched in bedrock, then secured to the hillside by steel cables about 5 inches thick and stretching 120 feet into the side of the slope.

“It’s like bolting the hillside back together, except you’re using huge bolts with tremendous capacity,” said Ralph Jeffery of American Geotechnical, which helped design what experts are calling a temporary fix.

The project, at a cost of $2 million to $3 million, is only the first phase of several that will be needed to save the hillside and rescue the community.

“This is something to stabilize it for now,” said Kathleen Strong, a San Diego attorney who represents the Niguel Summit Homeowners Assn. in a complex lawsuit that may be headed to trial next month.

Meanwhile, in the months since the houses tumbled down the slope, property values also have begun to slide, even as home prices soar elsewhere in Orange County. Some residents have received county notices of assessment reductions--in a few cases, up to 60%.

“It’s certainly an impartial voice confirming that their [home] values have declined as a result of the landslide,” said Vance Simonds, a lawyer who represents 52 homeowners whose houses were not destroyed but who believe their property values are suffering.

State law allows for “calamity reassessments” in case of events such as landslides, making the stabilization work all the more urgent as a signal that property values are being shored up by aggressive action, Simonds said.

The stabilization effort comes in the wake of a March 19 landslide that toppled three houses from the hilltop lots, destroying a fourth and crushing five condominium units in the Crown Cove complex at the base of the hill. Geological experts, acting on evidence of slope movement, had predicted several months earlier that a slide would occur, so most residents were evacuated in time.

But the slide was particularly violent and was visible to motorists, who could clearly see the $500,000 houses as they dangled over the hillside. The slide also upended and twisted the condo building below.

The property toll stands at 21 condos and nine houses destroyed or condemned.

Residents, victims and homeowners associations have sued Hon Development and the owner of home builder J.M. Peters Co., along with companies involved in grading and geotechnical work on the 1,400-home Niguel Summit development.

Constructed in the 1980s, Niguel Summit was designed and built around at least six old landslide areas that were graded, buttressed and altered to provide the building pads for the development. It is one of many of South County’s unstable hill areas where homeowners have encountered slope stability problems.

“This is very complex geology . . . and the slide mass makes it more complicated than it was,” said Reed Ruck, project engineer for DBM, the Seattle contractor installing the 64 concrete pillars being used as a wall to prevent a further landslide.

The 64 pillars will ensure that the hillside remains stable west of Via Estoril. But geologists have not decided how to shore up the hillside east of Via Estoril, where the slide took place. Also undecided is whether to rebuild the 21 condemned condos and the nine condemned houses.

The project began in mid-June and will continue at least until October as workers install the pillars along the top of the landslide, where the wrecked houses still lie as they fell five months ago; the land is too unstable to permit their salvage.

On Via Estoril, the street at the top of the landslide, parts of the houses remain, with views through gaping, open front doors looking to missing rear walls and patios and pools dumped dozens of feet down the failed slope.

In some houses, there are still signs of abandoned lives: neatly piled firewood in the garage of one house slated for demolition; shelves lined with bug spray and paint and a pair of Reebok shoes.

Down slope, the Crown Cove condos may never be the same. Security fences surround overgrown grass, mangled trees and upended buildings.

Attorneys have been meeting with mediators for months. Thomas Miller of Newport Beach, the attorney representing the Crown Cove homeowners association, said developers made a settlement offer last week. He said he cannot comment on the specifics, but called the offer “significant.”

“We’ve got homeowners displaced, homeowners living in a ghost town, everywhere over there you have debris lying around, and they can’t take much more,” Miller said. “Maybe it’ll be over soon.”

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Shoring up a Slope

Geotechnical contractors are building an underground infrastructure designed to halt an ancient landslide that reawakened in March and destroyed four Laguna Niguel homes. Excavation work on Via Estoril is expected to continue through mid-October. A look at how the subterranean system works:

Vertical Support--Caissons extend deep into bedrock

Boring Process

Crews will dig the last caisson holes later this week.

A) Drill holes for caissons

B) Lower rebar cage into hole

C) Fill with 4 truckloads of concrete

Horizontal Support--Grade beam forms T across top of caissons

Lateral Support--Tie backs keep the wall created by caissons and grade beam from migrating downhill

4) Anchor--Waler connects tie backs to the caissons

By the Numbers

Number of caissons: 64

Diameter of caissons: 3 ft.